2 stage cascade

[_HL4E_HalfLife_]

UPDATE!!

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

[ZENNZZO]

UPDATE!!

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

Yeah they are...alot better than plumbing valves and JB Weld...

[_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... 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 .

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 .

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??




Well today I finished brazing its a complete cycle now 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. 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

[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

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.

[_HL4E_HalfLife_]

She's a looker, she is.

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.

[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 ,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 , you can't slow a ac motor down buy just reducing the voltage like a dc motor . you will ruin your motor.!!!!!

[pythagoras]

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

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.