2 stage cascade

[_HL4E_HalfLife_]

This will be the beast behind my 2 stage cascade system im beginning soon. R22 or Propane for stage 1 and CO2,R404,or R502 for stage 2.

[berkut]

I think she's a little too big...

[Formann]

The picture of that compressor made by back hurt :p:

You couldn´t find a larger one? :D

Its a beast alright. :)

[runmc]

Could you point out the suction port and discharge port for us? :)

[Cr@sh_D1n3r]

pc ice do you mind telling me what L.R.A. means? is 71 too much :stick: ? Btw you compressor seems a bit BIG lol! that must make an insane ammount of noise but hell, I think it's gonna give you some nice results :toast:

Edit: I just saw that you compresor weight 72 LBS!!!!!!! hahaha don't drop it on the ground :p: Suction is 1/2 and discharge 3/8.

[afireinside]

God that thing is HUGE! Just use 1HPs and safe some room/noise/electricity...

[herefishy]

pc ice do you mind telling me what L.R.A. means?



LRA = Locked Rotor Amps. That is how much current the motor will draw whne the motor is seized up (broken). Doesn't mean much of anything, actually.

The nomencalture of the model number should indicate horsepower.

****-0075-***. The numbers in the middle indicate horsepower.

0033 = 1/3 hp

[wdrzal]

LRA = Locked Rotor Amps. That is how much current the motor will draw whne the motor is seized up (broken). Doesn't mean much of anything, actually.

The nomencalture of the model number should indicate horsepower.

****-0075-***. The numbers in the middle indicate horsepower.

0033 = 1/3 hp

correct on what LRA ,stands for. but its meaning is very important that why they reserve a space for it on every motor. the circuit breaker must always be lower than this number, by a safe margin. lets look at this compressor. RLA 5.4 and LRA 31. That tells me that under max charge/load the manufacture recommends the unit not draw more than 5.4 amps. the LRA 31 tells you that is the maxium number of amps the windings can draw if the rotor locks.So the circuit breaker on this circuit needs to carry the 5.4 amps without tripping and should not be over 31 amps. a 30 amp breaker is too close to the LRA and should not be used,A good choice for this compressor is a 15 amp breaker using 14 gauge wire or a 20 amp breaker using 12 gauge wire. a 10 amp breaker on a long wire run might also trip prematurly(too light). Notice that the higher the circuit breaker ,the larger wire size must be used(smaller number).This is to be certian that the wire does not melt before the breaker trips. Each breaker/fuse size has a minium wire size requirement that corasponds with it. Walt


edit this is for primary circuit protection,if it is a branch circuit the wire size must be able too carry 115% of the LRA.

I want to expand on this a little, you must look at the application to determine if the fuseing is to protect the device or to soley protect the wiring circuit.each application needs to be looked at in its entiry. take this application ,if this comressor was on a 20 amp circuit that would protect the motor ,now lets say he adds a fan to this circuit that draws .5 amps and has a Lra of 4 amps, if this circuit is not seperatly fused or thermally protected, the wire should be able to carry 115% of the LRA so the wire will not melt if the fan becomes locked,the motor would be ruined in this example but the wireto it would not melt.

[runmc]

Good explanation walt. :toast:

So the Locked Rotor Amps is basically on the compressor to tell us what size breaker and wiring to use and nothing more? :)

[wdrzal]

Yes, along with the run load amps(RLA). A margin must be left above the RLA for the added resistance of the wire run plus since all motor draw many times their RLA for a split second during start-up(iductive load) to close to the RLA will cause circuit to trip at start-up. All circuit breakes have a AIC rating (amps interupt circuit) that allow it to draw many times its rated trip load for short periods so that motors can start with out tripping breaker. the RLA and LRA can be thought of as a minium and maximium circuit limits plus a margin for safty on the upper limit. I would use no less than 20% ,so for a LRA of 31 a 25 amp breaker would be acceptable but no more. Walt

[_HL4E_HalfLife_]

Could you point out the suction port and discharge port for us? :)


Here you go.

[_HL4E_HalfLife_]

Yep she does weigh a ton lol. I tried looking up the specs on the copeland website and i tried googling it but i can't find the specs for this compressor anywhere. :( any help would be appreachiated.

[REDKEN]

Yep she does weigh a ton lol. I tried looking up the specs on the copeland website and i tried googling it but i can't find the specs for this compressor anywhere. :( any help would be appreachiated.
Sorry this (http://webcompressors.com/COPELAMETIC_SERVICE_COMPRESSORS.htm#RANGE!A619) is the only thing I could find and their distributor here (http://www.refrigerationsupply.com/copeland_compressors.html). Maybe you could sent them a PM or call? But didn't herefishy say it was a 1/3HP?

[wdrzal]

herefishy is right its definitly 1/3 hp ,I see if I can find the specs for this model,should have rebuild manual around too.

[_HL4E_HalfLife_]

yea redken thats what I had found too.

[Cr@sh_D1n3r]

thx for answer! I really apreciate it!

[herefishy]

So the Locked Rotor Amps is basically on the compressor to tell us what size breaker and wiring to use and nothing more? :)

NO! You would not want to pay for a 35Amp circuit for this compressor.

RLA = rated load Amperage. The RLA is somewhat indicative of what you would expect the compressor current to be, at the rated voltage, in the rated application. Good greif! A 35Amp circuit for a 1/3hp compressor?

:stick:

NOT!

[herefishy]

I couldn't find anything on the web either... but I havbe a 1995 United Refrigeration Catalogue with this compressor's information in it. The compressor is rated R-12 high/medium temperature (from +55F to 0F).

4,900 Btu/H R-12 at 55F evaporator (at 90degF condensing temperature),

1,150 Btu/H R-12 at 0degF evaporator (at 90degF condensing temperature)


Cheers!

[herefishy]

OH!

Also, the compressor is rated low temp (0degF to -40degF) R-502, as such:

2,400 Btu/H @ 0degF evaporator (90degF condensing temperature)

440 Btu/H @ -40degF evaporator (90degF condensing temperature)

So, it is a high temp R-12/Low temp R-502 little 1/3 horse compressor.

[Coyote]

This will be the beast behind my 2 stage cascade system im beginning soon. R22 or Propane for stage 1 and CO2,R404,or R502 for stage 2.

R404 and R502 are first stage refrigerants, theres no use to have them as 2nd stage. CO2 is a problem with oil, youll have to add some propane to make oil flow.

[_HL4E_HalfLife_]

OH!

Also, the compressor is rated low temp (0degF to -40degF) R-502, as such:

2,400 Btu/H @ 0degF evaporator (90degF condensing temperature)

440 Btu/H @ -40degF evaporator (90degF condensing temperature)

So, it is a high temp R-12/Low temp R-502 little 1/3 horse compressor.


That seems a bit small for a compressor of this size and valve port openings (10mm across). Are you sure the model and serial numbers are the same? Im still looking for some technical specs such as rpm's,run cap mfd,Start cap mfd,relays,etc.

[wdrzal]

I want everyone to be aware there is a differance between protecting a circuit with the proper size wire and fuseing so it does not get hot and melt and protecting a motor or compressor from overloads.There is also a differance in wiring primary circiuts from branch circuits.There are guides for circuit protection and motor protection in the NEC(national electric code) each circumstance must be looked at induvidually.

[skate2snow]

The size as absolutly nothing to do with the power...

And the size of that beast is because of the type... a lot of displacement though...

[chilly1]

Copeland used the same body size for a number of compressors up to 1/2 hp all they do is bore it out and add bigger pistons and use a bigger motor.

[_HL4E_HalfLife_]

The size as absolutly nothing to do with the power...

And the size of that beast is because of the type... a lot of displacement though...

Yep they do these serviceable compressors have alot more displacement than sealed compressors of the same rating do thus for every revolution this compressor makes theres an increased amount of btu's.

[herefishy]

That seems a bit small for a compressor of this size and valve port openings (10mm across). Are you sure the model and serial numbers are the same? Im still looking for some technical specs such as rpm's,run cap mfd,Start cap mfd,relays,etc.


Increasing the valve port size will decrease volemtric efficiancy (capacity) of the compression cycle due to re-expansion of compressed gas in the compression chamber.

I will refer to my Copeland Electrical data book for the electrical components for you. Even though the compressor model is not listed in the compressor search section of the Copeland website (because the model number has been superceded, I'm sure), You would likely find the model number and information in the Copeland Electrical Handbook.

Regards,

[Chris_F]

If you want real power I'd look for a good scroll compressor instead of a semi-hermetic one.

[_HL4E_HalfLife_]

If you want real power I'd look for a good scroll compressor instead of a semi-hermetic one.

The only scroll's i've seen around here are like 3ton and up thats too big!!. other than that I can pretty much get any compressor up to 1.5hp for free.

altho this compressor was made in 1987 it has never been used so its just as good as if it was built yesterday. :D

[_HL4E_HalfLife_]

I just had a thought, does anyone know if you can use Acetylene as a refrigerant? I never heard of anyone using this gas before as a refrigerant but as u know most gases can be used as a refrigerant gases.

Acetylene properties here:

http://www.c-f-c.com/specgas_products/acetylene.htm

It also has a very low boiling point seen here:

http://www.c-f-c.com/charts/alkynes.htm

[kayl]

no cant use acetylene as a refrigerant, cant remember why, i think it was because it was way to dangerous.

[GuGaCoSa]

Because it cannot work with copper tubes,NEVER use acetylene in refrigeration systems.

[gclg2000]

omg, ya don't do it.

[wdrzal]

Acetylene is a unstable gas ,it can not be compressed without a stabilizing agent.If my memory is correct its maxium working pressure is 15 psi and standard working pressures are below 7.5 psi. under NO circumstances should it ever be used as a refrigerant.

[kayl]

if you'r system is all steel and you have steel ball's to match..then run it.. :eek:

says the mad man that tried nitrous oxide.
Heehe dont use that either all it would take is an electrical short and :nono: :caution: :explode2:

[Tonic]

How does look reaction between acetylene and copper?

[_HL4E_HalfLife_]

Ok thats out. What about nitrogen?

[wdrzal]

nothing,if you can condense it

[Chris_F]

How about methane?

[gclg2000]

ICE, you used methan once didnt ya? I think he did, but it didn't hold load well.

[wdrzal]

read the chemical make-up of refrigerants. monochlorodifloroMETHANE,diclorotrifloroMETHANE,ec t,ect.........

propane is 90% methane

[gclg2000]

Sorry walt but what? Adding substiuant groups (or elements) to molecules totally changes the physical properties of the base molecule.

And what you me propane is 90% methane?

[wdrzal]

of couse it changes them that why methane is flamable and r22 is not, propane comes either from natural gas or oil, natural gas is mostly methane.

[wdrzal]

I got that wrong propane is in natural gas along with methane

[_HL4E_HalfLife_]

New pics!! This condenser has a capacity of 20,000 Btu's. The orignal motor for this fan was 220v so i get to get rid of it and put this 115v motor on it.Its a bit stronger than the old 220v motor as well.

Ps. The cap u see in pic 3 is just a point of reference to show the actual size of this condenser.

[wdrzal]

what voltage is the compressor?

[gclg2000]

If this is for cascade righ? I'd splice the condenser and use the bottom 1/3 of it or something for air condenser to help subcool the hot gas coming out of the compressor of the 2nd stage.

[_HL4E_HalfLife_]

Do u think I should use this compressor as a first stage or a second stage?

[gclg2000]

The enormous compressor in your 1st post?

[_HL4E_HalfLife_]

Ok guys I got the specs on this compressor.

[ellsworth]

the only reason it's so big is because it's a semi-hermetic...

[_HL4E_HalfLife_]

^Correct that also means its it serviceable. Since R502 has been long gone im trying to figure out what would be a good replacement for it. :confused:

[_HL4E_HalfLife_]

UPDATE!!.. Just finished building the evaporator/condenser today and it wasn't easy bending it into a loop as you can see lol. I have also chosen R-402a as a refrigerant for stage one because of its boiling point of -49.2c im anxious to see how low I can get stage one.

The project has been coming along slowly because i've been doing other things lately but feel free to post ur questions,suggestions,etc.

[uclajd]

Props & bonus points for using old, unusual equipment. :clap:

[ZENNZZO]

:shock2: :shock2: Geesus H christ man!...you must live really close to a substation? :shocked: :shocked:

[_HL4E_HalfLife_]

:shock2: :shock2: Geesus H christ man!...you must live really close to a substation? :shocked: :shocked:

Explain?

[ZENNZZO]

Explain?
POWER usage is all I was refering to bro...I was building all last month and if I wasn't testing or evacing down I was tunning one...the bill for the month was 250.00 USD... ;) It would be sweet to have an un-metered lead from a substation...lol

[_HL4E_HalfLife_]

POWER usage is all I was refering to bro...I was building all last month and if I wasn't testing or evacing down I was tunning one...the bill for the month was 250.00 USD... ;) It would be sweet to have an un-metered lead from a substation...lol

LMAO well the answer to ur question is no I don't heh, but this compressor won't be drawing that much 3.5 to 4.5 amps I would have to say.

I think i might have struck gold yesterday at work theres an old A/C thats been sitting in the storage area for about 2 years now and its a wopper its 115v 18000Btu's with a rotary compressor. Its been banged up and scratches on it so im gonna see what I can get it for.This would be wicked to use as my 2nd stage :eek: :slobber:

BTW 18000btu's is as high as you can go before switching over to 220v.

[n00b 0f l337]

Haha, now thats a score.

[ZENNZZO]

LMAO well the answer to ur question is no I don't heh, but this compressor won't be drawing that much 3.5 to 4.5 amps I would have to say.

I think i might have struck gold yesterday at work theres an old A/C thats been sitting in the storage area for about 2 years now and its a wopper its 115v 18000Btu's with a rotary compressor. Its been banged up and scratches on it so im gonna see what I can get it for.This would be wicked to use as my 2nd stage :eek: :slobber:

BTW 18000btu's is as high as you can go before switching over to 220v.
Hell yeah ya did...sharing is caring...lol...what else didja score?...Hmmmmm?

[_HL4E_HalfLife_]

How does it go for cap tube? Longer=slower response in load conditions but lower temps. Shorter=quick response in load conditions,not as low a temp in the end. Is this correct? And also how long is too long and how short is too short?

[_HL4E_HalfLife_]

UPDATE!! I did some brazing today for the high side u can see one of the joints I brazed just after the discharge service valve in pic 1, the other joint you can kinda see in pic2 entering the condenser. In case ur wondering about that copper tubing thats wrapped around the compressor,thats used to cool the compressor body and also will prevent liquid return to the compressor. I pressure tested those 2 brazing joints up to 205Psi for about 10 min than drew a vacuum for about 15min and the pressures held, so far no leaks :D

[pythagoras]

Wow, that compressors tiny :slobber: It looked huge in the first pick.

Using the suction line to cool that compressor is probably going to kill your evap temps.

Regards

John.

[_HL4E_HalfLife_]

Wow, that compressors tiny :slobber: It looked huge in the first pick.

Using the suction line to cool that compressor is probably going to kill your evap temps.

Regards

John.

Not at all because the cap tube will be brazed onto the big loop first so any gas that hasn't boiled off after it has left the evap loop will boil off in the compressor cooling loop.

Ps. Can someone answer my question about the cap tube.

[pythagoras]

Thats what you want to happen, but its probably not what will happen. It would be great if the heatoutput of the compressor just balanced the heat required to boil of any remaining refrigerent in the suction line.

But what are the odds of that happening? I'll bet you get massive superheat---high suction pressures---high evap temps!

Regards

John.

[_HL4E_HalfLife_]

Thats what you want to happen, but its probably not what will happen. It would be great if the heatoutput of the compressor just balanced the heat required to boil of any remaining refrigerent in the suction line.

But what are the odds of that happening? I'll bet you get massive superheat---high suction pressures---high evap temps!

Regards

John.

I bought a needle valve that im gonna use to manually adjust the flow of gas through the compressor cooling loop. and since noone was willing to help me with the cap tube :shakes: i've decided to try something I don't think anyone here has ever tried yet, I call it a 5 stage cap tube selector..thats all im gonna say about it for now ill post pics when its complete.

[_HL4E_HalfLife_]

BIG UPDATE!!

Picked up a liquid line filter drier and a sight glass. I also built my cap tube selector in the shop where i work today. In pic3 there are 5 different lenghts of cap tube starting from the left is the shortest one at 15 inches than 20",30",40" and finally 50 inches. Connected up the filter drier and the sight glass to the selector and mounted the selector in place.Attached the 5 cap tubes to the other ends of the needle valves shortest starting on the left again. I drew a bit of a vacuum to see if it would hold and I could hear air leaking in around the valve fittings (peices of s-h-i-t) so I whipped up some JB quik weld and gobbed up the fittings which you can see in the last pic and am gonna let it harden overnight. Tomorrow im gonna braze the 5 cap tubes into the loop and and recheck for leaks.

[ZENNZZO]

Did you put the flare fittings together w/ JB weld or did you really just gob in on the flare nut?

[_HL4E_HalfLife_]

Did you put the flare fittings together w/ JB weld or did you really just gob in on the flare nut?

I just put it around the fittings. JB weld is great for sealing leaks it gets rock hard,my boss where I work has used it many times for this.

[ZENNZZO]

I just put it around the fittings. JB weld is great for sealing leaks it gets rock hard,my boss where I work has used it many times for this.
interesting... ;)

[wdrzal]

BIG UPDATE!!

Picked up a liquid line filter drier and a sight glass. I also built my cap tube selector in the shop where i work today. In pic3 there are 5 different lenghts of cap tube starting from the left is the shortest one at 15 inches than 20",30",40" and finally 50 inches. Connected up the filter drier and the sight glass to the selector and mounted the selector in place.Attached the 5 cap tubes to the other ends of the needle valves shortest starting on the left again. I drew a bit of a vacuum to see if it would hold and I could hear air leaking in around the valve fittings (peices of s-h-i-t) so I whipped up some JB quik weld and gobbed up the fittings which you can see in the last pic and am gonna let it harden overnight. Tomorrow im gonna braze the 5 cap tubes into the loop and and recheck for leaks.

compression fittings like those on the needle valves are not used in refrigeration because they leak and they can blow off .Since the tube slides into the fitting they can be brazed,you must dis-assemble the valve first so the heat dosn't ruin it.just braze the tube into the valve,throw the nuts and compresson rings away.

[ellsworth]

i've seen people use hand adjustable expansion valves. i think that would be perfect for your application.

[_HL4E_HalfLife_]

compression fittings like those on the needle valves are not used in refrigeration because they leak and they can blow off .Since the tube slides into the fitting they can be brazed,you must dis-assemble the valve first so the heat dosn't ruin it.just braze the tube into the valve,throw the nuts and compresson rings away.

I have thought about brazing the valves but the valves are made of brass I think won't that be a problem?

[wdrzal]

you can braze them using 15% or higher silver rod and flux.be sure to dis-asamble them. they may even leak around the valve stem since these are not designed for hvac/r use. But I think you can tighten the packing nut enough so they won't leak,but no gaurentees.

Keep in mind plumbing parts are not refrigeration parts, you will never find a refrigeration part that uses compression rings, they are either braze in or flare.Places lke lowes and home depot do not sell any refrigeration parts .

[_HL4E_HalfLife_]

you can braze them using 15% or higher silver rod and flux.be sure to dis-asamble them. they may even leak around the valve stem since these are not designed for hvac/r use. But I think you can tighten the packing nut enough so they won't leak,but no gaurentees.

Keep in mind plumbing parts are not refrigeration parts, you will never find a refrigeration part that uses compression rings, they are either braze in or flare.Places lke lowes and home depot do not sell any refrigeration parts .

Silver rod?? is that just another saying for silfoss? if so thats what i've been using to braze the copper joints refrigeration grade silfoss.

I've been getting some of the parts such as the valves at home hardware.

[wdrzal]

I use a rod made by victor called "silverflow" it contains no silver,its a phos-copper rod it is for cu to cu use.you have to look at the breakdown of elements listed on the package. They call is silverflow because they want you to think it flow like silver rod. they work well on cu but have a higher melting point.They do not work on brass.

the point is just because a rod has "silver" in its name it may not have any in the rod.

[_HL4E_HalfLife_]

UPDATE!!

I scraped using those brass needle valves for these (pic1&2) its not pretty but these valves were built for refrigeration. :D

[ZENNZZO]

UPDATE!!

I scraped using those brass needle valves for these (pic1&2) its not pretty but these valves were built for refrigeration. :D
Yeah they are...alot better than plumbing valves and JB Weld... :toast:

[_HL4E_HalfLife_]

You bet they are but i had to replace 1 of them because i couldn't get the dam thing leak free at the brazing joint since its brass... :upset: so replaced it with one that has a flare fitting on it and as i type this up right now the whole selector peice is sitting in a 30hg vacuum till tomorrow afternoon when i get off work ill put it under a real stress test for a few hours of about 300Psi if it can hold that without leaking than it never will :D.

edited by runmc for language

[ZENNZZO]

...when i get off work ill put it under a real stress test for a few hours of about 300Psi if it can hold that without leaking than it never will :D.
just make sure to put some loops in the feed to is so vibration won't get ya...

[_HL4E_HalfLife_]

just make sure to put some loops in the feed to is so vibration won't get ya...

What vibration?? :confused:




Well today I finished brazing its a complete cycle now :p: im too tired to take some pics tonight but i will tomorrow. My only remaining problem is the flare nuts are leaking no matter how tight i make them tomorrow im gonna try smoothing the flare with some 1000grit sandpaper that should fix any leaks.I also removed the MO from the compressor and replaces it with POE oil for the R402A. I've been using a special freon to clean the insides of the copper tubing after i braze it i dought any of you have ever used this gas before since it hasn't been made for 20+ years now its R11 this freon was designed for cleaning systems such as after a burnout has occured. You won't believe what came out of my condensor when i used this R11, old oil and god knows what else im gonna flush R11 through my system again before i charge it and run it. My workplace has a big 100Kg barrel of this stuff thats been sitting around for many years:D. R11 has a boiling point of 23.7c

[_HL4E_HalfLife_]

Heres the pics i promised.Today i sanded the flares that were leaking and i managed to get them all leak free after several hours for fine tuning :woot: :rocker: :banana3:

[esdee]

Heres the pics i promised.Today i sanded the flares that were leaking and i managed to get them all leak free after several hours for fine tuning :woot: :rocker: :banana3:


:slobber: Very Very nice work!

[n00b 0f l337]

Once this is done you gotta get an oven...

I mean prescott.

[_HL4E_HalfLife_]

Thx esdee

noob-Thats what im saving up for, im switching over from 478 to LGA775 so i need the works, ill be getting a 3.6E0

Today i've just been vacuuming it out and using R22 to help remove moisture.

[_HL4E_HalfLife_]

Either today or monday im gonna get some more R11 and flush out the whole cycle removing any metal shavings,brazing remains (what i call flakes) and anything else thats still in the copper tubing. After that im gonna vacuum it out 1 or 2 more times than im gonna charge it with R402A and fire it up and test the system on each cap tube and ill post initial results for each one.

[Chris_F]

She's a looker, she is. :toast:

[_HL4E_HalfLife_]

She's a looker, she is. :toast:

lol huh?


Today I flushed out the whole system with some more R11 and I added some more POE oil up to the correct level and since i had the front of the compressor off I took a pic so u can see what it looks inside, only took one pic tho but u can see the 2 rods. Tomorrow shes common alive. :D :slobber: :toast: :clap: :banana:

[Jort]

you might check that seal again, just clean it of and put some poe oil onto it and put it back together. the oil is to stay the seal soft so it doesn't crack and to avoid leaks:)

[_HL4E_HalfLife_]

you might check that seal again, just clean it of and put some poe oil onto it and put it back together. the oil is to stay the seal soft so it doesn't crack and to avoid leaks:)


No worries i checked it and its not leaking.

[_HL4E_HalfLife_]

Ok after some moisture problems i managed to get the system up and running but ill still need to replace the liquid line filter drier. But i've hit a snag, on the longest cap tube setting (50") i can't get the temp to go any lower than 5.3F what could be limiting this? On that setting my pressures were 15/175Psi and the compressor was drawing about 2.5 to 3amps.I have the condenser motor on a dimmer switch to control its speed and to get down to 5.3F the motor was doing maybe 200...250Rpms out of a max of 1550 any higher than 250 and my temps went up.

My guesses are that the compressor is simply too small for this first stage being that the condenser was built for 18000btu capacity and all. Any help on this would be appreachiated.

[_HL4E_HalfLife_]

erm..............HELPPPPPPPPPPPPPP

[ellsworth]

erm..............HELPPPPPPPPPPPPPP


is it just me or is 50" of cap tube really short...
i used 10ft (.028") on my last propane system.

[n00b 0f l337]

Is your suction line frozen over?

[ellsworth]

Is your suction line frozen over?

it might not be...remember he wrapped it around the shell of the compressor?

[wdrzal]

STOP , you can't put a motor on a dimmer switch to control speed you will burn it up.!!!!

also those motors get hot wrapping the suction line aroud the compressor is adding to much load

[ellsworth]

the best way to protect the compressor without adding load is to make a big u bend in the suction line or just get an accumulator.

[_HL4E_HalfLife_]

STOP , you can't put a motor on a dimmer switch to control speed you will burn it up.!!!!


O yes you can I have been doing it for the past 10 years and i havn't had a single dimmer switch die because of it.

[_HL4E_HalfLife_]

Even if the cap tube is short I still should be getting lower temps than -15c!! Look at a window A/C there cap tubes are generally between 15" and 25" long and when there converted in to chillers were seeing temps as low as -35c.

I got this working A/C yesterday for 20 bucks ....canadian :D,Maybe I should use this compressor for my stage one instead and use the semi for stage 2?

[wdrzal]

O yes you can I have been doing it for the past 10 years and i havn't had a single dimmer switch die because of it.


Its not the dimmer switch :stick: , you can't slow a ac motor down buy just reducing the voltage like a dc motor :rolleyes: . you will ruin your motor.!!!!! :nono:

[pythagoras]

Its not the dimmer switch :stick: , you can't slow a ac motor down buy just reducing the voltage like a dc motor :rolleyes: . you will ruin your motor.!!!!! :nono:

AC dimmer switches dont work that way Walt. They dont reduce the voltage they switch the current off and on at variable rates. They have a rheostat conected to a triac. The rheostat controls how much time the triac is in the off and on position, not sure how healthy this is for a compressor though.

I still think the real problem is the suction line coiled around the compressor. It should be easy to check if that is the case.

Regards

John.

[wdrzal]

a standard dimmer switch like you use on a light does reduce the voltage. they do make varialbe speed controls for ac motors that change the hertz to control the speed ,but they are not called dimmers.

a light dimmer will harm the motor, should have said reduces current


you are correct I also think the coil is adding too much load.

[pythagoras]

Modern dimmers dont work that way either Walt:

http://home.howstuffworks.com/dimmer-switch.htm

Regards

John.

[_HL4E_HalfLife_]

Its not the dimmer switch :stick: , you can't slow a ac motor down buy just reducing the voltage like a dc motor :rolleyes: . you will ruin your motor.!!!!! :nono:

Don't get me started on what a motor can and cannot do. Motors are my hobby! I've rewound motor stators that have burned out i've replaced sleeve bearings with ball bearings and more I even own the second edition Fourth Impression, Fractional horsepower electric motors By Cyril G. Veinott. And i've seen ceiling fans that use a dimmer switch and if thats not enough take a look at the pic below. Nuff Said! :owned:

[wdrzal]

you won't see the voltage drop on a standard multimeter because the sample rate is to slow. however you will see the voltage drop on a scope meter or ocillascope

[_HL4E_HalfLife_]

I still think the real problem is the suction line coiled around the compressor. It should be easy to check if that is the case.

Regards

John.

I asked my boss at work that question and he agrees with me that the tubing wrapped around the compressor won't effect the temps in the loop since the compressor coil is after the loop so most of the gas has already boiled off in the loop section before it even reaches the compressor coil. So I still tend to think that the compressor is too small for stage 1. Prove me wrong.

[pythagoras]

I wasnt denying that there will be momentary voltage drops, you would have to precisely control the switching time to the ac cycle to avoid an off period at the top of the cycle, I'm just pointing out that modern dimmers modus operandi isnt to vary the voltage as part of the operation.

_HL4E_HalfLife_ We dont own people in here, we have discussions sometimes we are right sometimes wrong, its not a competition ;)

Regards

John.

[wdrzal]

every ceiling fan I ever installed that had a dimmer had a rectifier and used a dc motor.

[wdrzal]

dimmers that drop the voltage are also still in sold, usually the cheaper ones

[pythagoras]

Well I dont think thats true, when you add heat the pressure in the coiled section increases-----That is definately fact.

Now if the pressure is increased in this section and its directly connected to the evap the pressure there will increase. If the pressure in the evap increase the evaporating temperature of the refrigerant also increases.

In these systems the only major pressure differences are across the expansion device. There is minimal pressure difference between compresor discharge and expansion device entrance, and a similar minimal pressure difference between expansion device exit and compresor suction.

Regards

John.

[pythagoras]

Well I dont think thats true, when you add heat the pressure in the coiled section increases-----That is definately fact.

Now if the pressure is increased in this section and its directly connected to the evap the pressure there will increase. If the pressure in the evap increase the evaporating temperature of the refrigerant also increases.

In these systems the only major pressure differences are across the expansion device. There is minimal pressure difference between compresor discharge and expansion device entrance, and a similar minimal pressure difference between expansion device exit and compresor suction.

Regards

John.

Actually this is very easy to demonstrate: Stick a hairdryer on that coiled section and watch your evap temp rise ;)

[wdrzal]

as far as the loops even if it alreadly boiled off it can still asorb load in vapor form. thats why you insulate suction lines.

[_HL4E_HalfLife_]

I know ill have to insulate but that still don't account for the roadblock i've run into. My suction pressure was around 10Psi now for R402A that should make the loop somewhere around -35~-45c and yet im nowheres near there and the sight glass is full.

[pythagoras]

If thats 10 psig thats equates to an evap temp of between -10 and -12 Centigrade, pretty close to what you have.

Regards

John.

[pythagoras]

Oooops :( 10 psig for 402a, thats what you have right? Is -32C.

Now if you have a pressure of 10psig and an evap temp of -15C, one of those readings are wrong. What are you using to measure the temps, if you have already said, I apologise I will read the thread carefully now.

Regards

John.

[wdrzal]

I looked this up to be sure I was correct, this is from copland: heat entering the suction line from ambiant air can cause capacity losses from 10% to 15%.this is why its cost effective to insulate a suction line. thats just a uninsulated suction line in ambiant air, you have it wraped around a hot compressor.that could be over 1/2 your capacity or more gone. you only should have about 10 to 15 degrees of superheat to prevent liquid return,thats it.

[wdrzal]

back to using dimmers, even a modern dimmer that uses a reostat and a triac will harm a ac motor. a ac motor controler uses the same triac, thats where dimmers got the idea from,but because a light dimmer only controls a single filiment the reduction rate doesn't matter. In a ac motor the commutator is divided into many sections for the number of armature windings.Without getting to complex , When the motor is turning, a speed controllor senses these breaks in the commutator and matches the rate at which the motor is turning and supplies even power to each winding. A light dimmer can not do this,and a unbalanced load codition will exist.

I really don't think expensive speed controllors would sell if a dimmer was all that is needed.

[_HL4E_HalfLife_]

Pythagoras- Im using a UEi Digital thermometer. As for my gauges i know there giving an accurate reading. So I would say something else isn't right,couldn't it be because the compressor simply isn't pumping enough fast enough to get the temps any lower?

wdrzal- As i said earlier i've been using dimmer switches to control motor speeds for 10 years now and have never had a dimmer switch die or have a motor on a dimmer switch burn out! thats gotta telling you something.

[wdrzal]

remember the pressure/ temp relationship is only if both liquid and vapor are present.

also a full sight glass apears clear , so does a empty one. they look the same you have judge which it is.

that compresor is designed to run on one speed why would you want to slow it anyhow?

as to dimmers , you can't getto rig stuff in the real world or it will hang you someday. Overloaded stuff causes more fires than anything,don't you think if it could safely slow a ac motor that way the manufacturer would say so!!!!


read up on how a variable speed controlers work, similiar to a triac dimmer but with a very important differance. those triac's were used in motor controllors long before dimmers started to use them.

[_HL4E_HalfLife_]

remember the pressure/ temp relationship is only if both liquid and vapor are present.

also a full sight glass apears clear , so does a empty one. they look the same you have judge which it is.

that compresor is designed to run on one speed why would you want to slow it anyhow?

as to dimmers , you can't getto rig stuff in the real world or it will hang you someday. Overloaded stuff causes more fires than anything,don't you think if it could safely slow a ac motor that way the manufacturer would say so!!!!


read up on how a variable speed controlers work, similiar to a triac dimmer but with a very important differance. those triac's were used in motor controllors long before dimmers started to use them.

1st of all who said anything about slowing the compressor down???
and 2nd the sight glass i have has a FULL word in it that can only be seen when its full.

BTW Please stop treating me like im a rookie at this!

[wdrzal]

you did say condensor motor, thought you said compressor motor. my mistake. never seen a sight glass that says full, what I said about them is true . .

[_HL4E_HalfLife_]

you did say condensor motor, thought you said compressor motor. my mistake. never seen a sight glass that says full, what I said about them is true . .

I could take a pic of it if u want to see.

[wdrzal]

I beleive you, I,m more courius on how it works, what happens to make the word "full" appear. could you explain that.

[kayl]

whats with all the valves?? why so many

http://www.xtremesystems.org/forums/attachment.php?attachmentid=31856

[runmc]

Take that suction line off of the compressor.. :stick:

I love your experiment with the captubes :clap: Cool Idea :cool: - I hope it works.

[_HL4E_HalfLife_]

whats with all the valves?? why so many

read back a page or 2 its all explained there.

[_HL4E_HalfLife_]

Thx runme :woot:

[_HL4E_HalfLife_]

I beleive you, I,m more courius on how it works, what happens to make the word "full" appear. could you explain that.

Its kinda hard to explain so ill just post some pics of it empty and full.

[wdrzal]

thats neat, but I never seen a glass like that.No idea how it works. LOL

just a thought, most sight glasses have a moisture indicator, is that telling us its full of liquid or full of moisture? No, since you got a pic in both positions I sure its saying full of liquid.

Is there a manufacturer mark on it?

[wdrzal]

does the flow of liquid make it flip up or what, if you have bubbles,say half gas and half liquid is it half way up?

I use a electronic sight glass so I rarely buy visiual ones,

[_HL4E_HalfLife_]

thats neat, but I never seen a glass like that.No idea how it works. LOL

just a thought, most sight glasses have a moisture indicator, is that telling us its full of liquid or full of moisture? No, since you got a pic in both positions I sure its saying full of liquid.

Is there a manufacturer mark on it?

all thats on it is made in USA and M.B. CO.

[_HL4E_HalfLife_]

does the flow of liquid make it flip up or what, if you have bubbles,say half gas and half liquid is it half way up?

I use a electronic sight glass so I rarely buy visiual ones,

My guess is that the liquid changed that second glass inside from being cloudy to clear making the "FULL" word clear to see.

[_HL4E_HalfLife_]

Does anyone know how many Psi this waterblock could withstand?

[wdrzal]

did you buy that locally or get it on ebay?


talkig about the sight glass

[_HL4E_HalfLife_]

did you buy that locally or get it on ebay?


talkig about the sight glass

I got it at the shop where i work. Its a gold mine there :D

[_HL4E_HalfLife_]

Ok today i removed the compressor loop and my temps are the same AS I SAID ALL ALONG THE COMPRESSOR LOOP WON'T EFFECT TEMPS IN THE EVAP!! :slapass: :slap: :nono:. I still think the compressor is too small.

What about the waterblock?

[wdrzal]

a water block is not a evaporator. and the loops did definely affect system temps. a given compressor and condensor can oly handle so much load, adding any heat to the system increases that load.

[_HL4E_HalfLife_]

Still think the compressor is too small..........

[kayl]

read back a page or 2 its all explained there.


I read the last 2 pages where you had the pic of the valve assembly (in particular post 79 onwards, too much to read before)
There doesn’t seem to be an explanation on how it is meant to work.
Are the valves used for the secondstage? or first stage? and is that pipe the HX they are all connected to?

I did read 50” of capilaary line used, I also read that it didn’t get cold.


If you remove any plastic parts and braze the water block together (if its brazed already just pressure test it)
And it holds the pressure that you tested the valve assembly to, it should work fine.

[_HL4E_HalfLife_]

Kayl the valves are attached to 5 different lengths of cap tubing i did this so i can change the cap length without having to braze it and can be done while the system is up and running.

U really think that waterblock could withstand 250Psi??

BTW kayl if ur following this thread u really should be reading it all :nono:

[_HL4E_HalfLife_]

Well I had a bit of a setback today my rotary vacuum pump has stoped pumping it still spins but no pumping action. So tomorrow im gonna build a duel compressor vacuum pump. If everything goes ok ill have pics of it on here by tomorrow night. :D

[meke]

Well I had a bit of a setback today my rotary vacuum pump has stoped pumping it still spins but no pumping action. So tomorrow im gonna build a duel compressor vacuum pump. If everything goes ok ill have pics of it on here by tomorrow night. :D

that's exactly the reason why I buy a brand new vacuum pump.

2.hand or used compressors has a limited capacity to remover the air and moist from the system.

[_HL4E_HalfLife_]

Like i promised heres a pic of my new duel compressor vacuum pump. Mannn does she ever pull a vacuum quick :D

[kayl]

ok i seen now, didnt realise they all just capubes.
the daul vacuum pump will work well.
try compound system, series compressors.
im not hope full now a second look at that evap.
maybe test it under water just in case splits.
i think i have to stop drinking on the internet not see properly :toast: and not reading properly :slapass:

[JSU]

It looks as if parralel compressors (yours) will only evacuate to a certain lvl faster. Compressors in series should give a better vacuum though.

[_HL4E_HalfLife_]

Well i finally switched compressors the 1hp rotary is on stage one now i ran out of gas so ill have to wait till monday to get a new jug of 402A. I also might try using 402A as a 2nd stage gas too because at 20hg it will be at -80c ill just have to see how things go with stage1.

I also finished making some touch-ups on the vacuum pump.

[_HL4E_HalfLife_]

UPDATE!!

I picked up a brand new jug of R402A at the shop yesterday :D. also I decided to remove the receiver mainly because those things will hold soo much liquid its not funny and its kinda of a waste and if i have to let the gas out of the system because of a problem (unless i recover it) ill just have to refill the whole receiver again.

Today I finally the system going on the new compressor and I was right the other compressor was too small and yet noone agreed with me on that :nono: :slap:

Also today I also reached a goal i had set way back when i first started building this to hit the -40c mark on 1st stage. :D Now i'm gonna start insulating the evap im hoping to get another 5 to 10c by doing this and making small tweaks to the charge and adjusting the fan speed to find the sweet spot.

Comments suggestions on other improvments would be appreachiated.

[_HL4E_HalfLife_]

ANOTHER UPDATE!! :D

Just finished my first layer of insulation. Im gonna go to the hardware store to see what i can use as a second layer. Once i finished the first layer i turned the system on again and it went right down to -49c than for some reason it slowing came up to -25c than slowly when down -45c and stayed there. I think the reason it came up is because the thermometer probe moved and wasn't in good contact with the copper tube.

[kayl]

Nice job on the insulation. :toast:
From the look of it its under charged judging on low side pressure compared to pressure charts, you are gonna need more capacity for second stage. Whats the temperature of suction line first stage out of the hx?

[Waus-mod]

Looks really nice... keep up the good work. Like kayl said; nice insulation :)

[_HL4E_HalfLife_]

Nice job on the insulation. :toast:
From the look of it its under charged judging on low side pressure compared to pressure charts, you are gonna need more capacity for second stage. Whats the temperature of suction line first stage out of the hx?

The sight glass is full so i don't think its low on charge.

As for the temps i ran it again tonight and this time it didn't come back up in temp so it was the probe out of place. :D and also it went past -50c unfortunitly thats the limit of the thermometer with the probe on it anything lower than -50c just reads as LO. :( I dono what im gonna use now i can't afford a $200 thermometer :mad:

[_HL4E_HalfLife_]

I'm low on options for a 2nd stage gas to use im on a very limited budget so i can't afford any 1150 or Co2. :( Has anyone tried using R22 and adding a small amount of helium or another extremely cold gas to lower the boiling point? Would it work?

[kayl]

The sight glass is full so i don't think its low on charge.

As for the temps i ran it again tonight and this time it didn't come back up in temp so it was the probe out of place. :D and also it went past -50c unfortunitly thats the limit of the thermometer with the probe on it anything lower than -50c just reads as LO. :( I dono what im gonna use now i can't afford a $200 thermometer :mad:


sight glass does come in handy no guessing.
mainly say that casue ya had low pressure with not good temps.
but a loose probe does it to ya. i found 8degs on the autocascade attacked right.

i had the same problem when i did my first cascade temp probe only going to -50c, unless you can make one ya really forced to get one other wise guessing temps. look on ebay that not too dear if order them from the US. Under 140us.

how expensive is c02 in your country, the welding stuff is normally dirt cheap.
really all the cascade gasses are expensive except c02. what about really low grade of 1150 like the 99% stuff is cheap compared to 99.5? after that it gets way more expensive.

[_HL4E_HalfLife_]

I have no clue what it costs here kayl and i wouldn't know where to look for 1150 or the co2.

As for the thermometer is it possibile to remove a low temp limit? like im sure the probe would read below -50c but its just that the thermometer isn't displaying it below -50c

[f00t]

run over to canadian tire and grab a paintball co2 cannister. a 20oz one is about $60 and to fill it is about $10

[kayl]

Yes its a lot of fun trying to source cascade stuff in your own town.
I know im the only person in Australia doing cascades so no one to help me source stuff.
Its a lot lot harder than ppl think. Have to get account etc and enquire etc.
Some places they wont even let you get 1150.
Gkiing is from Canada and he got a bottle of c02 for his autocascade project.
http://www.xtremesystems.org/forums/showthread.php?t=53292&page=1&pp=25

From memory stuff in Canada and Australia is similar prices what gkiing said. I think he rented his bottle, give him a pm or something more info if helps.

You should be able to get most gases needed (well at least ethane, co2 and ethylene) from aire liquid or boc gas, they are located all over the word in different countries.
Im getting mine from boc gas, just get an account and order what you need over phone, can even have it delivered to your house.
I wouldn’t buy regulators through them, cost too much, get them through a torch store and just an industrial one, a lot cheaper.

Also with the temp gauge, the sensor may read lower temps, but you will need to map the voltages to relate to a given voltage.
The reason why they limit the meter to -50c as not read that accurate. The -50c meters arnt always accurate anyways.
You only need one good gauge, then get xtra probes and its like you have several metres

[_HL4E_HalfLife_]

Hmm that all sounds interesting. This co2 cannister for paintball guns how would i connect it up to the gauges? would i have the braze a check valve on it?

Well i got alot of stuff coming in over the next week or so, 2 more A/C's with 12000Btu rotarys and i got this compressor today (in pic) no cost 11300Btu's 115v 50LRA.

[f00t]

where are you getting all this stuff from? it took me 3 months to find two good compressors for my cascade.

as for a c02 bottle. go to your local air liquid supplier/ welding supply shop. they can definetle hook you up with some c02. if im not mistaken, a regulator is about $90/ bottle $200 (i think)/ and a fill is about $50 for small personal bottles.

i made my co2 paintball adapter from one of those propane torch thingys. i got a fitting for the paintball bottle, brazed it onto the bottom of the torch thing, trimmed the central shapft down a couple of mm, and brazed a shraeder onto the top

[_HL4E_HalfLife_]

where are you getting all this stuff from? it took me 3 months to find two good compressors for my cascade.

as for a c02 bottle. go to your local air liquid supplier/ welding supply shop. they can definetle hook you up with some c02. if im not mistaken, a regulator is about $90/ bottle $200 (i think)/ and a fill is about $50 for small personal bottles.

i made my co2 paintball adapter from one of those propane torch thingys. i got a fitting for the paintball bottle, brazed it onto the bottom of the torch thing, trimmed the central shapft down a couple of mm, and brazed a shraeder onto the top

Hehe at the shop where i work its a gold mine theres compressors there that range from being brand new to being 20 years old and 20 year old compressors weather they have been used or not won't installed in a system anytime soon such as the compressor i got today its ment for a window A/C and nowadays you won't see a window A/C with a recipricator compressor you'll see a rotary. Next time im at the shop ill take a few pics and post them here.

I've already went to a gas store and to buy co2 from there u need to start a contract which is $80 and u have to pay that each year to get the tank serviced so im not doing that i think ill look up on the paintball co2 cannister because thats all ill need.

[wdrzal]

you can purchase a tank, then just pay for contents. I own every tank I have and thats quit a few.

[_HL4E_HalfLife_]

you can purchase a tank, then just pay for contents. I own every tank I have and thats quit a few.

Still buying a tank u need a contract from them i asked and thats what he said.

I just found this so this is what im gonna get. :D

http://www.canadiantire.ca/assortments/product_detail.jsp?FOLDER%3C%3Efolder_id=140847439 6670082&ASSORTMENT%3C%3East_id=1408474396670271&bmUID=1119583767287&PRODUCT%3C%3Eprd_id=845524443259432&assortment=primary&fromSearch=true

[_HL4E_HalfLife_]

Today i got those 2 A/C's i mentioned in a previous post. I had to replace the run cap on 1 of them to get it going but other than that they both work. There both identical 12000Btu 1hp rotarys 62 LRA 12 RLA 115v they both have the exact same rotary as the one i got on my first stage :D.

[Cr@sh_D1n3r]

I just got a 20LBS bottle for about 150$ cnd @ BOC GAS they probably have a store near by. The bottle is mine and when I need to fill it up, it will only cost me 35$. I had no contract or anything else to do with thems just passed by and asked for 20 lbs co2. He even gave me a nice cga320 to cga 580 adapter for free...

[_HL4E_HalfLife_]

What oil should be used with co2 anyway?

Edit: What do you guys think about this oil separator? would it work?

[Tonic]

CO2 doesn't catch any oils, that's why it's better to use R134a/R22/R290 for oil transporting

I don't think that idea should work fine :

- it's horizontal, the power of gravity works weakly
- too small area for dropping droplets (only two pipes)
- the flow of refrigerant should transport droplets which layed on bottom of this wide pipe to separator's outlet

I would go to classic oil separator, vertical and wide pipe filled by metal wool

[_HL4E_HalfLife_]

So why would i want to use an oil separator if co2 doesn't carry any oil? Again what oil should be used?

[Cr@sh_D1n3r]

This is the thing man...you don't need an oil separator in a co2 auto-cascade. You need one in a co2 cascade because the carbon dioxide dosen't carry the oil well. You can use hydrocarbon and fluorocarbon based oil.

[_HL4E_HalfLife_]

This is the thing man...you don't need an oil separator in a co2 auto-cascade. You need one in a co2 cascade because the carbon dioxide dosen't carry the oil well. You can use hydrocarbon and fluorocarbon based oil.

But why would u want to carry the oil? all the oil is for is to lubricate the compressor not to travel through the system. What is hydrocarbon and fluorocarbon based oils? MO? POE? AB?

[Gray Mole]

You wand oil to be carried in the part of the circuit that oil is required, your compressor. Therefore you want the oil to be carried:

Out of the compressor --> to the oil separator --> back to the suction line --> and into the compressor.

This will ensure complete lubrication of the compressor as the oil is dispersed in the refrigerant in the 'oil circuit'.

If you had oil that didn't freeze up and block the system, an oil separator would be unnecessary, and in single stage systems the temperature isn't cold enough, so oil sep's aren't used.

As for compatibility of oil, I'm curious myself, as I'd like to use R22 and 508b in an autocascade, and I'm unsure if they are fine using the same oil. POE was the oil I'd planned to use.

Gray

[Cr@sh_D1n3r]

On a normal phase-change system there's no oil separator because the refrigerant carry the oil by it self. I guess you will use r290 so just make your phase sep and propane will take care of the oil transportation. If you want to build one go ahead dude but I'm telling you, you don't need one. You can use mineral and poe oil with it.

[_HL4E_HalfLife_]

Hmm from what i know compressors are self-lubricating at least recip ones are they pick up the oil from the bottom of the shell and up through the shaft to the bearings just take a look at the video i posted in another thread heres a link.

http://binary-side.net/tmp/opencompressor.avi

[Cr@sh_D1n3r]

ok then, build a system and fill with propane and let it run for 2 hours. Then make all the gas leak from the discharge and you'll end up with an messy oily pipes.

[Waus-mod]

Youve got nice ac units there. Hope you will make it!

[_HL4E_HalfLife_]

ok then, build a system and fill with propane and let it run for 2 hours. Then make all the gas leak from the discharge and you'll end up with an messy oily pipes.

Dude i know oil travels in any regular system im not stupid and i think ur misunderstanding what my point is. My point is if co2 doesn't carry any oil like u say than an oil separator shouldn't be needed because all the oil will remain in the compressor.If u watched the video i posted u see that recip's
are self-lubricating im just not 100% sure if rotarys do the same thing. Im gonna cut the top off my old rotary compressor i used as a vacuum pump and find out of they do self-lubricate.

[Cr@sh_D1n3r]

sorry I didn't meant to piss you off...lol dunno why I thought it was a autocascade for a moment sorry :P. If you use co2 as 2nd stage then you need to put some propane in it because you will end up with a clogged evap because dry ice will form in it. I'm not sure that under pressure the compressor isn't blowing oil through the discharge. Some expert could help us on that one.

[_HL4E_HalfLife_]

I don't have any 290 will some 402A be fine?

[f00t]

r420 will do the job but from what i have heard berkut say r22 is the best and r290 is supposed to be pretty good too.

ps: r290 = propane

[_HL4E_HalfLife_]

r420 will do the job but from what i have heard berkut say r22 is the best and r290 is supposed to be pretty good too.

ps: r290 = propane

what is r420? or do u mean 402a?

Im wondering if 402a would work since it boils colder than R22 does so it would be less likely to effect the temps the co2 reaches.

[Tonic]

Also, oil must be cooled, probably that's why a traveling through whole unit is needed, it cools at evaporator and suction

[_HL4E_HalfLife_]

Also, oil must be cooled, probably that's why a traveling through whole unit is needed, it cools at evaporator and suction

Don't forget that the gas return is what really cools the compressor. Also having oil in the evap reduces cooling efficiency because its coating the walls of the copper tubing. Like i say im gonna cut open my old rotary vacuum pump this evening and see if its self-lubricating or not i think that will help resolve this issue. On another note how would u build an oil separator?

[f00t]

lol yeah i ment r402a. not enough sleep

[_HL4E_HalfLife_]

I cut open the rotary compressor and there is a hole in the middle of the shaft possibily for the oil but ill have to do further cutting to get a better look at the bottom. Heres some pics of it.

[_HL4E_HalfLife_]

UPDATE!!

I drilled some holes and mounted the second compressor in place, it just fits :p:. I also brazed a desuperheater to the discharge of the compressor and ran it around so its mounted behind the fan thats on the condensor for stage one so an extra fan is not needed here :cool:.

[_HL4E_HalfLife_]

Can only upload 5 pics at once :mad:

I pumped some R11 through the condensor for the 2nd stage to remove the moisture in it. Thats R11 in the icecream container in liquid form cool huh?

[Cr@sh_D1n3r]

really nice :banana: ! I was wondering why is your hx made that way? I mean why you didn't put simple pipe insulation? Hurry I want to see the temps so we can compare each others system :D (I made a cascade and auto-cascade yesterday but I can't tune it yet because I have no probe that goes lower than -55c) Good luck on that "thing" !

[kayl]

The cascade is really coming together nicly, should see some noce temps with that.


Today i got those 2 A/C's i mentioned in a previous post. I had to replace the run cap on 1 of them to get it going but other than that they both work. There both identical 12000Btu 1hp rotarys 62 LRA 12 RLA 115v they both have the exact same rotary as the one i got on my first stage :D.


they should make fine compressors, unless been used too much.
they look like old r22 ones (what refrigerant are they?)
more than likly mineral oil i would say. just drop the oil and replace it with new stuff, also give ya an idea of what work it done.
those 2 compressors are capable of -100c with a co2/r290 cascade. ;)

as for oil separator i would just use one just in case to be safe.
the r290 will carry some of the oil to the separator and then back to the compressor when return valve opened. and ya dont want oil in capillary line to add to blocks second stage.



I don't have any 290 will some 402A be fine?

i think that r402 does actually consist of some r290 r22 and something else.
Google search on it and find composition.
Just try it and see who ya go
its expensive stuff though, $38kg compared to r507 $18 i just need a frigin license, unfair.

[Cr@sh_D1n3r]

r22 / r125 / r290 ratio : 38 / 60 / 2 . I think r125 is mainly a firefighting agent.

[_HL4E_HalfLife_]

Man you guys post quick lol and yes they are R22 compressors im not sure about the oil in them heres a pic of them the clear oil (one on the left) is the oil that came out of the rotary i got on 1st stage. So what the heck is it? AB? Ester? Synthetic?

[Cr@sh_D1n3r]

my bottle of mineral oil have the same oil color as the one on the left if that help you.

btw imo the oil color you have mean your compressor is in perfect condition! I mean not even a bit dark! that's great!

[_HL4E_HalfLife_]

my bottle of mineral oil have the same oil color as the one on the left if that help you

O yea i almost forget this clear oil seems to carbonated as well it was making bubbles for quite some time after i removed it from the compressor. I've never seen mineral oil do that before so im not so sure that it is mineral oil. Any idea what color AB,Ester, and Synthetic oils are?

[_HL4E_HalfLife_]

btw imo the oil color you have mean your compressor is in perfect condition! I mean not even a bit dark! that's great!

:D :D :D

[Cr@sh_D1n3r]

I once removed the oil from a rotary compressor with mineral oil in it and it did it :) lol we are flooding the forum :P do you have msn ? would be cool to have each other address :)

[_HL4E_HalfLife_]

I once removed the oil from a rotary compressor with mineral oil in it and it did it :) lol we are flooding the forum :P do you have msn ? would be cool to have each other address :)

This isn't flooding, were providing useful information for rookies out there.

Ps.yes i do have msn.

[_HL4E_HalfLife_]

On a side note for those of you that are wondering what im using for a torch...

[Tonic]

This isn't flooding, were providing useful information for rookies out there.



Indeed, it's nice to read your coversion

Acetylene/Air torch, if you can, shot photos of torch at action :)

[_HL4E_HalfLife_]

Indeed, it's nice to read your coversion

Acetylene/Air torch, if you can, shot photos of torch at action :)

LOL sure np next time i braze something ill take a pic heh.

Again about the type of oil i should use i didn't really get a direct answer on this so since some 402a is gonnna be added anyway which has R22 and R290 in it i decided to just leave the MO in the compressor since MO works best with R22/R290 this shouldn't be a problem should it?

Ps. where would i find copper/steel wool?

[Tonic]

You can buy those wools in markets/supermarkets/hipermarkets. They're used to wash the dishes :D

About oil, sorry, at the moment I can't understand, I'm to sleepy.. :PMaybe tomorrow I'll read a few late
pages and try to answer

[_HL4E_HalfLife_]

You can buy those wools in markets/supermarkets/hipermarkets. They're used to wash the dishes :D

About oil, sorry, at the moment I can't understand, I'm to sleepy.. :PMaybe tomorrow I'll read a few late
pages and try to answer

Ahhh i was wondering about those dish washing wools i just wasn't sure if it was the same thing as what you guys were using. So what do you guys use to keep the wool in place in the oil separator?

Heres that pic u requested tonic. :D :woot:

[_HL4E_HalfLife_]

Just a thought..is there any reason not to use manifold gauge hoses to connect up the evap? I know they would have to be tightened alot to prevent leaks but they would be perfect since there designed for high pressure.

[Cr@sh_D1n3r]

Yes there's simple one : it's not made for such low temperature. The hose will freeze up and will get incredibly hard to bend so all vibration will go to the cpu :P

[f00t]

deigned for high pressure but not cold. if your gonna be at -70 some with a rubber hose the slightest abrupt bend could crack it

[_HL4E_HalfLife_]

So what can i use?

[chilly1]

Stainless flex hose.
and for oil with r402 any of the standard oils are fine.

[_HL4E_HalfLife_]

Stainless flex hose.
and for oil with r402 any of the standard oils are fine.

Heyyy chilly welcome to my growing thread lol.

Stainless flex hose? never heard of it. Is it available at any hardware store?

[Tonic]

I think no one use something for keeping wool in place. Just fill oil separator from bottom to top with wools

Nice flame :)

EDIT :

I didn't notice new post, this topic is really fast in growing

Stainless flexible hose - it's a hose made by stainless steel and it's corrugated (and thanks to that it's elastical)

There are photos

http://img.alibaba.com/photo/50230323/Stainless_Steel_Corrugated_Hoses_for_Gas_Cooker.jp g
http://www.gorajec.net/raven/noiselessDD/szron2.jpg

[meke]

Stainless flex hose? never heard of it. Is it available at any hardware store?

Go to a hydrolic equipment store, or look in net.

they are quite cheap and fine. You can cut and braze to copper easily.

http://img.photobucket.com/albums/v217/meke_oocay/DD_Projects/Project_SLI/sliblock9.jpg

[chilly1]

Heyyy chilly welcome to my growing thread lol.

Stainless flex hose? never heard of it. Is it available at any hardware store?
Well when you next go th the hardware store look for the stainless steel gas flex line. about 10.00 at homedepot they are a little large but will work.

[_HL4E_HalfLife_]

Small update today. I went to the shop and built my oil separator. I dono if the separator is large enough this is the largest ID copper tubing the shop has so i hope its good enough. Does it matter where i put the separator weather its before or after the condensor just as long its before the cap tube?

I also found some copper wool in the kitchen last night so thats what i used i hope noone comes looking for it :p:

Since theres no place around here to get a block of copper or a place to machine it into an evap i had to take a different route one im not sure will work or not. Its built but im not ready to post the evap on here just yet.

[Tonic]

Better before condenser, otherwise oil will lay on condenser's pipes and make worse heat transfering between air and gas

[_HL4E_HalfLife_]

Better before condenser, otherwise oil will lay on condenser's pipes and make worse heat transfering between air and gas

Dangit i already brazed up the condensor o well i suppose i could rip it apart again :( It was gonna go compressor-desuperheater-condensor-oil separator-cap tube.

Other than that the separator is ok for size and all?

[Tonic]

What are separator's dimensions?

BTW, what you call a condenser in second stage, it's really a desuperheater

[_HL4E_HalfLife_]

What are separator's dimensions?

BTW, what you call a condenser in second stage, it's really a desuperheater

The desuperheater is the small loop of tubing behind the fan when i say condensor im talking about the HX.

As for the separator's size i hope this helps.

[Tonic]

The desuperheater is the small loop of tubing behind the fan when i say condensor im talking about the HX.

Ah, then ok :)



As for the separator's size i hope this helps.

I assume that there length unit is inch, in my opinion this oil separator isn't a quite tall and too low, the
ID length is fine, it should work. But fill it fully with wools.. :) PC_ICE had make a lot of oil separators
like as your (but with caps on ends), you may ask him what he thinks about it

[_HL4E_HalfLife_]

Ah, then ok :)



I assume that there length unit is inch, in my opinion this oil separator isn't a quite tall and too low, the
ID length is fine, it should work. But fill it fully with wools.. :) PC_ICE had make a lot of oil separators
like as your (but with caps on ends), you may ask him what he thinks about it

It's already filled with copper wool. Now that i know its ok im gonna braze it to the system. BBL with pics.

[wdrzal]

Ahhh i was wondering about those dish washing wools i just wasn't sure if it was the same thing as what you guys were using. So what do you guys use to keep the wool in place in the oil separator?

Heres that pic u requested tonic. :D :woot:



look at this pic of his acetylene/air torch here, there is a important lesson here. the flame hase 2 parts the primary flame and the secondary flame. the blue pencil tip is the hottest and should be just touching the pipe for the most heat, but the most important lesson of this pic is in the secondary flame. Notice the green color, This is a idication the copper tube is up to brazing temperature. learn to read your torchs color pattern and this will tell you when jouint is ready to braze.

Look for dull red copper tube & green secondary flame
ps :nice photo!!!

edit,why didn't the photo didn,t move with the quote look at post 200 in this thread

[_HL4E_HalfLife_]

why didn't the photo didn,t move with the quote look at post 200 in this thread

I don't understand what you mean. :confused:

[wdrzal]

I wanted to bump the photo,in fact the was the most important part.

[_HL4E_HalfLife_]

UPDATE!!

I installed the oil separator this evening found a nice little spot for it right in front. I flared 2 peices of 3/8 tubing for the oil separator valve and braze a cap tube on to one of the 3/8 peices than ran the cap tube along the bottom under the second stage compressor and up the other side. I brazed the other end of the cap tube to a peice of 1/2 tubing that i had already brazed a shraider valve onto for servicing the system at an earlier date i just need to braze this 1/2 peice onto the suction line on the compressor.

I also bought some switches and wired up both compressors and the condensor fan with the dimmer switch. The condensor fan will come one when first stage is switched on.

Would 90 inches of cap tube be too long for the second stage?

[kayl]

Systems is looking nice good place for the oil seperator, I would of thought that 90” of capillary line would be too short for the metering device for the secondstage (low stage), what ID would you be using ??
or do you mean 90” of capillary line for the oil return from the oil sperator?? Oil separator line can be as long / or as short as you want, any ID would be fine.

[_HL4E_HalfLife_]

Systems is looking nice good place for the oil seperator, I would of thought that 90” of capillary line would be too short for the metering device for the secondstage (low stage), what ID would you be using ??
or do you mean 90” of capillary line for the oil return from the oil sperator?? Oil separator line can be as long / or as short as you want, any ID would be fine.

It is for the second stage and not the oil separator. How do u measure the ID of a cap tube anyway??? its just so dang small :confused: :confused:

Heres a pic i couldn't add in the last post because of the 5 pic limit.

[kayl]

It is for the second stage and not the oil separator. How do u measure the ID of a cap tube anyway??? its just so dang small :confused: :confused:

Heres a pic i couldn't add in the last post because of the 5 pic limit.


looks good.
it looks like 0.026" (0.6mm) or 0.028" (0.7) by eye have to check packet label.
but as long as it doesnt flood too much should be ok.
i always start long and cut short, co2 is cheap. some time will be suprised what a longer lenght of capillary can do :stick:

[gkiing]

Good grief, what are all the valves for? That's ghetto to the max!

You measure the id of a captube with a little tool that has rods the same diameter as the outside of the captubes, and you hold it against it and check.

[Tonic]

There are a few of capillary tubes which go to high stage evaporator ;) They have different lengths, those valves
are supposed for experiments (?), you open first valve (other are closed), temperatures are no good, then you
close first valve and open second valve. And you repeat it until you will know which capillary tube will provide
the best evaporating temperature.

[_HL4E_HalfLife_]

There are a few of capillary tubes which go to high stage evaporator ;) They have different lengths, those valves
are supposed for experiments (?), you open first valve (other are closed), temperatures are no good, then you
close first valve and open second valve. And you repeat it until you will know which capillary tube will provide
the best evaporating temperature.

What he said.

I don't have that tool for measuring cap tubes nor do i have the packet label. As for the length u think that 90" is too short being that its either 0.6 or 0.7mm?

[_HL4E_HalfLife_]

Well heres my evap (its all i could think of to use) my problem is i don't know what can i do to make a wavy path inside this unless you guys can think of another way to make an evap. :stick:

[f00t]

check out lardarse's end cap evaps. their very simplr to make and cheap too

[_HL4E_HalfLife_]

[QUOTE=f00t]check out lardarse's end cap evaps. their very simplr to make and cheap too[/

End cap evaps? I think i know what ur refering to. Ill take a look around next time im at the hardware store.

[Aphex_Tom_9]

[QUOTE=f00t]check out lardarse's end cap evaps. their very simplr to make and cheap too[/

End cap evaps? I think i know what ur refering to. Ill take a look around next time im at the hardware store.
yeah i would try and make one of those. that flattened pipe business dosent look very promising

[_HL4E_HalfLife_]

Not much to report today other than getting some end caps to use as my evap.Ill need to get my torch refilled either on saturday or monday i don't have enough gas left in it to put my evap together. :(

[JSU]

You dont plan on opening more than one of those valves (on the cap tube) at one time do you? It doesnt look as if you have enough on each one of those though looks can be devieving. Why didnt you buy a txv for the price of all those valves. It looks like you have a nice project over here. I cant wait to see the final product.

[_HL4E_HalfLife_]

You dont plan on opening more than one of those valves (on the cap tube) at one time do you? It doesnt look as if you have enough on each one of those though looks can be devieving. Why didnt you buy a txv for the price of all those valves. It looks like you have a nice project over here. I cant wait to see the final product.

No only 1 valve will be open at a time.All the valves are used i just got em from the shop and they costed nothing.

I saw ur post in my other thread,so now u really think im ready to be building this?

[kayl]

ya got the evap, now just need some co2 and ya cooling.
do you have a copper plate?? to fiinish it?

[JSU]

OMG I cant believe no one has answered what oil is for in a system. Oil in a system has to be compatible with the refrgierant being used. AKA. The oil has to absorb some of the refrgierant (i guess it would do this like water and co2). Once you pass the suction line and all the refrigerant is boiled off the oil which is cool goes into the compressor. It then continues to release any refrigerant left in it which cools down the compressor. The reason for doing it this way as apposed to having liquid come into the compressor is b/c liquid is not compressable and the oil which the refrigerant absorbed in it i guess is. It seems like the oil takes the refrgierant from a hp absorbed liquid to a lp gas. Hermetic compressors work this way. Rotarys dont fully benefit from this therefore you have to make sure to have a lower superheat than normal.


No only 1 valve will be open at a time.All the valves are used i just got em from the shop and they costed nothing.

I saw ur post in my other thread,so now u really think im ready to be building this?

Does my opinion effect the building of this? :D

[_HL4E_HalfLife_]

ya got the evap, now just need some co2 and ya cooling.
do you have a copper plate?? to fiinish it?


The new Canadian Tire store that just opened here (biggest one in the province) has co2 tanks for paintballs so im gonna get a 20oz for $54.99 and is refillable is that a good deal?

Kayl its not here at home but theres some 2" ID caps at the shop ill just cut the sides off 1 of thoes.

For the evap i saw that the one stockhatch did of the lardarse's evap he drilled large holes in the side of each end cap. I have a bit different idea for that what if i drilled 4 smaller holes on each side and drill them on an angle so the liquid will be forced down toward the base of the evap would that be more effective?

[_HL4E_HalfLife_]

OMG I cant believe no one has answered what oil is for in a system. Oil in a system has to be compatible with the refrgierant being used. AKA. The oil has to absorb some of the refrgierant (i guess it would do this like water and co2). Once you pass the suction line and all the refrigerant is boiled off the oil which is cool goes into the compressor. It then continues to release any refrigerant left in it which cools down the compressor. The reason for doing it this way as apposed to having liquid come into the compressor is b/c liquid is not compressable and the oil which the refrigerant absorbed in it i guess is. It seems like the oil takes the refrgierant from a hp absorbed liquid to a lp gas. Hermetic compressors work this way. Rotarys dont fully benefit from this therefore you have to make sure to have a lower superheat than normal.



Does my opinion effect the building of this? :D


So what are you saying JSU are u saying i did something wrong with the oil? :confused:

[JSU]

no, you guys were just wondering what oil does and why you have to have it circulate.

[pythagoras]

no, you guys were just wondering what oil does and why you have to have it circulate.

Its better not to have the oil circulate, however when you cant stop the oil circulating it needs to be miscable with the refrigerant in order for the oil to be returned to the compressor, its sole purpose is to lubricate the moving parts, not to aid with cooling of the compressor. Thats the job of the suction vapour and the condensor fan also aids here.

Regards

John.

[JSU]

sorry thats not the case. iam sure they could come up with a way of lubricating the compressor without having the oil circulate. btw chilly1 told me about the oil being used to cool the compressor ;) .

[_HL4E_HalfLife_]

Ok good. So about my evap would doing what i said in the previous post help or no?

[pythagoras]

Its called an oil seperator ;) But the ideal would be an oil less compressor.

Oil circulating coats the condensor and evaporator reducing their efficiency.

Trust me, Chilly1 would love a fool proof and cheap method of not having any oil circulating :D

Regards

John.

[pythagoras]

It certainly wouldnt do any harm, although I doubt the thickness of the end caps would really direct the refrigerent towards the base

Regards

John

[_HL4E_HalfLife_]

It certainly wouldnt do any harm, although I doubt the thickness of the end caps would really direct the refrigerent towards the base

Regards

John

Thats what ill do than and see how it works.

[wdrzal]

look at cryonic refrigeration , they use asorbers, they are sponges for oil, the problem is they don't release it,they are expensive and not reusable,they must be changed and oil has to be added to the pump.

[_HL4E_HalfLife_]

UPDATE!

This update is just redoing some stuff to stage 1. I've been having some problems with the temps sometimes it only goes to -20c other times it goes to -40c the point is the temps were all over the place and wern't stable at all so i recovered most the 402A from the system and once it was all out i changed the filter drier (new one in pic) this one is a bit longer then the last one. I also removed a bullet piercing valve from the suction line and brazed on a T and a schrader valve.
After that was all done I vacuumed the system with the duel compressors and i ran the torch over all the lines and the condensor to help remove all the moisture than recharged the system. I had the first valve open (15" captube) and the temp went right down to -43.5c and stayed there thats pretty dam good for 15". I closed off the first valve and opened the second valve (20"cap) and the temp droped down to -47.3. So being pleased with the results so far i closed off the second valve and opened the 3rd (30" cap) and thats where i stoped. See 2nd pic for reason (The Thermometer's low limit is -50c.) Ill have to buy a meter that can go down to -120c at least before i try that last 2 valves.

Ps. Sry about quality of 2nd pic i had to turn the flash off otherwise u can't
read the guages :(.

BTW what is the record on xs for the lowest first stage temp?

[Waus-mod]

Nice results... good work :D

[JSU]

Its called an oil seperator ;) But the ideal would be an oil less compressor.

Oil circulating coats the condensor and evaporator reducing their efficiency.

Trust me, Chilly1 would love a fool proof and cheap method of not having any oil circulating :D

Regards

John.

oil seperaters are not used in single stage hermetic compressor systems. With the second stage of a cascade the suction line is much colder than normal allowing more cooling so you dont have to rely on the oil to cool the compressor. We would all like a oil less system but thats the way these are designed to work ;)

[_HL4E_HalfLife_]

Can anyone conferm the boiling point of R764(sulfur dioxide) im getting mixed results about its bp.

Here is said that its bp is -76c
http://www.wc101.com/guides/refridgeration/page6.htm

Here its said that its bp is -10c

http://www.xtremeresources.com/forums/attachment.php?attachmentid=11714

If it is -76c thats good because i have access to R764

[saratoga]

Wikipedia claims -10C.

[n00b 0f l337]

Yeah and isnt it quite toxic? Weren't you going to do Co2 like kayl?

[gkiing]

sulphur dioxide is terrible stuff to work with.. ruins vacuum pumps and yes, its toxic.

[_HL4E_HalfLife_]

I guess they should correct that bp than. I had asked a while back with no answers :mad: if adding some Nitrogen to the co2 mixture will lower its bp since Nitrogen has a much lower bp (-195.9c)?

Also I think im using 0.028 or 0.026 cap tubing what should work better?90"(7.5 feet) or 120"(10feet)