How to wire a Hitachi rotary compressor ???

[Gray Mole]

http://www.soleusair.com/compressor/...SG473EA1NC.pdf

That compressor, while listed as R22, is the most similar in capacity to yours that I could see.

Obviously getting the correct datasheets would be best, but an approximate value can normally be used for Rotaries. I don't know if I would recommend that to the 'layman', but it can be done.

100% of all mid to small size rotaries I've used have all been capacitive run compressors.

For the 1/2HP Hitachi rotaries, I use 20uF capacitors.

For the 3/4HP ones, I use 30uF capacitors.

For 1HP, I used both 30 and 35uF capacitors.

Some of the Rotary compressors I've used were old or discontinued, and I could not source a datasheet even from the original manufacturer.

At that point, I researched very similar compressors based on application, LRA, displacement, etc., and found enough information to approximate the correct run cap, and have had no problem with that.

Keep in mind though, that run cap application is more critical than start cap.

If you have too large a start cap, it does not pose the same risk as too large a run cap. A start cap does not run for very long, and in it's worst case normally only kills the compressor.

A run cap can lead to overloading and fires, as stated in previous posts.

I will not recommend a particular run cap for you, but I would recommend reading that PDF, particularly near the end that shows run cap application for this series of compressor. The most suitable and most universal run cap in that list appears to be the 400vac, 30uF cap. That is what I've used primarily on 3/4hp rotaries of this general type with no failures to date.

As stated though, it would be best to wait for a reply from Hitachi for the correct datasheet.

Cheers

Gray

[Stelios]

Thanks Gray . Right now i'm searching for any information regarding motor types etc ... Lot's of information on google .

I also read that a very smal run capacitor will not let the motor run , while one more close to the recommended value will make it work (but it won't give the exact needed juice so it'll need more time to reach full speed) ...

I'll send one more mail to Hitachi-eu.com . Tommorow they are back to work also .

[wdrzal]

Fire Hazard From Terminal Venting With Ignition

Oil and refrigerant can spray out of the compressor if one of the terminal pins is ejected from the hermetic terminal. This "terminal venting" can occur as a result of a ground fault (also known as a short circuit to ground) in the compressor. The oil and refrigerant spray from terminal venting can be ignited by electricity and produce flames that can lead to serious burns or death. When spray from terminal venting is ignited this is called "terminal venting with ignition."

The above scenario can happen with non-flammable refrigerants as the oil is flammable,add flammable refrigerants and the effect can be multiplied many times,add a compressor with air still inside and a catastrophic explosion is possible.

This is one of the Dozens of ways to seriously hurt or kill yourself or burn your home down most people in this forum I,m sure never heard of or are not aware of the many other possibilities that DO happen.. Playing with line voltage and capacitors is not Child's play or for people not responsible enough or educated enough to take electricity seriously .

NEVER GUESS about correct WIRING connections.IF in doubt, STOP

This is one reasons why I try to stay away from electrical tips in this forum as I have no way to judge what a person knows or does not know. This is especially true when someone shows up with a problem and you don't have any or limited experience with this user in the PAST to judge his ability by. As most here are aware, the answer to your question is here in the archives,it may take a little reading to find your answer, but that is exactly what is needed for those who "ACT" first ,then ask questions Later.

I always recommend everyone buy a good refrigeration book that covers all the proper ways to build or service a refrigeration system including the electrical aspects. Determining capacitance is only for the experienced & someone who understands all aspects of electrical motor design & the differences in motor types(hermetic refrigeration compressors are all induction motors)and the problems of mismatched components CAN cause. Its impossible to give all the necessary warnings and possible things to check for in a single post or thread.

Its best to find correct wiring diagram for that compressor and use FACTORY recommended capacitance if either start or run capacitors are used.

There is a learning curve, and calculating capacitance as well as building a cascade as you eluded too it not advisable until you gain more expertise.

The people are here to help you, but you must do your part TOO, in educating yourself enough FIRST, by reading, to proceed in a SAFE responsible manner.

[{.bLanK} GoD]

Its impossible to give all the necessary warnings and possible things to check for in a single post or thread.

You do your best tho walt , and for that, most of us are very greatful.

[Stelios]

Fire Hazard From Terminal Venting With Ignition

This is one of the Dozens of ways to seriously hurt or kill yourself or burn your home down most people in this forum I,m sure never heard of or are not aware of the many other possibilities that DO happen.. Playing with line voltage and capacitors is not Child's play or for people not responsible enough or educated enough to take electricity seriously .

NEVER GUESS about correct WIRING connections.IF in doubt, STOP

This is one reasons why I try to stay away from electrical tips in this forum as I have no way to judge what a person knows or does not know. This is especially true when someone shows up with a problem and you don't have any or limited experience with this user in the PAST to judge his ability by. As most here are aware, the answer to your question is here in the archives,it may take a little reading to find your answer, but that is exactly what is needed for those who "ACT" first ,then ask questions Later.

I always recommend everyone buy a good refrigeration book that covers all the proper ways to build or service a refrigeration system including the electrical aspects. Determining capacitance is only for the experienced & someone who understands all aspects of electrical motor design & the differences in motor types(hermetic refrigeration compressors are all induction motors)and the problems of mismatched components CAN cause. Its impossible to give all the necessary warnings and possible things to check for in a single post or thread.

Its best to find correct wiring diagram for that compressor and use FACTORY recommended capacitance if either start or run capacitors are used.

There is a learning curve, and calculating capacitance as well as building a cascade as you eluded too it not advisable until you gain more expertise.

The people are here to help you, but you must do your part TOO, in educating yourself enough FIRST, by reading, to proceed in a SAFE responsible manner.

I know what you mean ... and i understand your acts . That's the way every professional with lots of experience would say . I'm not so active here in XS and this makes it harder for me to prove or to show what i know .

I don't believe that everyone who builds Single stages & cascades knows how motor works , or how many types are ... or how do they connect the wirings ... I know some guys that don't know a thing about thermodynamics !
My experience with eletronics & electricity begins at 1983 ... 7 years old ...
I'm studying physics & maths in the university here in Greece . There was never a reason to read and study about motors ... ... till now . :p

PS .It's difficult writing in other than native language and trying to explain some things...

[wdrzal]

I understand exactly what you are saying................you don't need to know how to calculate capacitance correctly for a motor to get it to run, or wire it correctly. You do need the wiring diagram with the capacitance listed and enough knowledge of basic electrical wiring and RESPECT for electricity to know how to wire it correctly and safely. You should never proceed like you did. If you are studying physics or even had physics prior to a university,grades 9 to 12(high school in USA)you should understand basic wiring as magnetic Fields and electricity are usually taught throughly because we live in a world now that would come to a halt without electricity. Below is a wiring diagram that by either by using all or part of it covers almost all the compressors we deal with.I would think someone at a university level would take the time to research and find the correct info. or ask a professor at the university as I,m sure your physics professor possess the information you seek and can explain it in you native language.BTW I only posted this about a hundred times or more. your compressor probably does not need the start capacitors and relay,but their is no way of me knowing unless you can give accurate readings of the windings resistance that I can trust or have the wiring diagram for that compressor. you can take a compressor that just has a run capacitor and add start capacitors to give it a boost in hard start conditions. by I,m going to end here. I believe this is your first compressor you ever wired,by you statements. We want to share information and teach but SAFETY in always the number 1 priority here at XS. Ask before proceeding.

[Stelios]

Thanks Walt for your valuable help .

I have wired 3-4 different motors ... But all of them had already the relay & the start capacitor and it was easy . And the most importand thing is that i had the PDF's to see the wiring. This compressor is the first one that i can't find any info. In fact it's the first rotary compressor i'm trying to use . All others were recip .
As far as the electricity & electromagnetism lessons ... that was 8-10 years ago in high school . I believe next year i'll have to study these lessons again at the university. I have forgotten a lot of things ...

Today i went to the refrigeration store . Regarding the datasheet i'll have to make a phone call tomorrow as the owner was not there today . He's the only one that can possibly have the datasheet.

The boys there told me that a 30-35MFD would do the job fine because that's what the 9000BTU A/C units are using . So , they gave me one running capacitor at 35MFD/450V .

Now , connnecting the capacitor like the diagram , it would be :
One capacitor terminal to RUN , the other one to Start .
Also from the mains outlet , one wire to OLP & in series to Common .... and the other wire to the capacitor terminal that has the RUN terminal connected.

I also found it's PDF : http://www.comarcond.com/pdf/pdf_uk/..._04_r2/mka.pdf

I'm thinking to wait till tomorrow for the datasheet if i'm lucky .
No replies from Hitachi also ...

[Forsaken1]

I checked with several supply houses here in the states.No luck.Have a call into hatachi also.Waiting for there reply.

[Stelios]

I checked with several supply houses here in the states.No luck.Have a call into hatachi also.Waiting for there reply.

Much appreciated !
Thanks !!

[Stelios]

I called the store & they found the electrical specifications ... It just needs 35uf/450V run capacitor .

So , i connected the capacitor like i wrote about 2-3 posts above .
I charged with 6 bars of R404A just for test . The motor starts , the low side gets down to -20/-25inhg but the highside can't get more that 180psi .
Condenser is cold , discharge line is cold . Motor begins to make strange noise . A few cm after capillary ends temperature went from 25C to 20C .
I stopped the motor and checked the pipework . Filter/drier is new . No restriction in capillary. No leaks (tested with a TIF electronic leak detector) .
I also tried with 8 bars static pressure and no difference . High side pressure couldn't get more than 180psi .

I removed the motor and tried it on air . Suction sucks air , but discharge is not strong . I mean ... my 1/7HP embraco can put out more pressure...

[star882]

You're running it on 240v, right?

[Stelios]

You're running it on 240v, right?

Yes .

EDIT:

Wanted to try the 2nd motor ... So , removed the plastic caps , brazed the appropriate pipes & put 2 valves .
I tried it on air and it had the same difficulty to up the pressure .
The noise of the 2 motors is the same . Maybe it's strange for me as i have never seen a rotary works in front of me ... so i assume i'm making a mistake here ...

Is it possible to REQUIRE ONLY R410A ???? I have R410A only for one charge , that's why i wanted to test first with R404A .
POE oil is compatible with both R404A & R410A ...

[expansionvalve]

Shortage of refrigerant?
I'd probably pulse charge liquid till I see roughly 220~250psi head.
It's a bit tricky trying to advice on what you should look for with very little system info.

[Stelios]

Shortage of refrigerant?
I'd probably pulse charge liquid till I see roughly 220~250psi head.
It's a bit tricky trying to advice on what you should look for with very little system info.

I tried a few minutes ago and gave a little more charge . Pressure ups a little bit ... Maybe it needs more . Next thing is to try with R404A and 10bars of static pressure .

EDIT :

Static pressure of 10bar .... While working , discharge up to 220Psi and begins to feel warm . Capillary output at 13C .
I'll put some more inside ...
I can't believe it ! Thing thing is huge comparing to what i have used so far ...

[Moc]

:P In a Rotary your static pressure is much higher than in a normal compressor. Normally I have more than 12bar!!

[Stelios]

:P In a Rotary your static pressure is much higher than in a normal compressor. Normally I have more than 12bar!!

That's it !
You see , i haven't played with a rotary again and i don't know how they work ...
So ... i put about 13-14 bar of R404A , and the PlateHX went down to -25C . I few minutes later , all pipes froze and finally i got a -15C a few inches before the compressor accumulator . HX stayed at -22C .
Highside pressure with a 120cm Delta on the condeser was about 200psi , and lowside about 0 psi .

Now i have to make the insulations and change the gas to R410A . Then i'll have to complete the 2nd stage.

I checked the compressor body temperature and was about 83C . Is this normal for R404A ?

Thanks all of you for your help !!!
See you on my cascade building thread soon .

[Gray Mole]

Guys, a R410 compressor is normally designed with a slightly lower compression ratio so that it's able to work with R410.

R410 has a high discharge pressure and is VERY hard on normal compressors. Generally compressors made for R410 are set up with this in mind.

That's very likely why you need such a high static pressure for 404a.

I would recommend either 402a or just R410 in these compressors for optimal performance.

Beyond that though, I would love to try one with something like R22/R116 blending, as I think the compressor would deal with the high pressure of 116, without the failure rate of more 'standard' compressors.

A temp of 83c is just fine in a Rotary. The temp safety switch on most of mine was about 150c cutoff. I found most ran between 90 and 100c under load. Rotaries that are not cooled by liquid injection tend to run at fairly high temp.

Gray

[Stelios]

Thanks Gray for the information . Tomorrow i'm getting some more R410A .

PlateHX temps went down to -45C steady with R404A and no insulations .

[runmc]

Remember R410 runs at a higher discharge pressure, as the Mole previously said , so build accordingly.

[Stelios]

Remember R410 runs at a higher discharge pressure, as the Mole previously said , so build accordingly.

Of course i'll be more carefull . I have also pressure tested the pipes up to 500Psi . In the past i have worked with R410A with my danfoss SC18CL .

[Stelios]

How should i measure superheat on this compressor ?? (Rotary with accumulator) .
Should i measure before accumulator , or after accumulator ?

Gray mole wrote here : "So not bad anyways, and that was tuning it for 10c superheat at the suction accumulator bottom before the short return pipe ."

But wdrzal wrote here : "Just take them on the suction line 3 to 6 inches from accumulator."

Which is the proper way ???


Also , will it do any good to insulate the accumulator ???
I found a post from Shamino in VR-Zone here :"they dont usually insulate a/c compressor's integrated accumulator but u shd when u run it for pc use as you will wanna run into a vaccuum or close to it, insulatin the accumulator is very important as these compressors are desinged to run high suction pressure while we are using them to ruin into vaccuums."

[Xeon th MG Pony]

Well after serching the forums and what not I figured I'd ask in here rather then making a new one, any one have the electrical pdf for a 2K-17-C3-R12-6A Matsush-ita Thanks.

I have every thing but its current ussage and its cap ratings.

[Stelios]

How should i measure superheat on this compressor ?? (Rotary with accumulator) .
Should i measure before accumulator , or after accumulator ?

Gray mole wrote here : "So not bad anyways, and that was tuning it for 10c superheat at the suction accumulator bottom before the short return pipe ."

But wdrzal wrote here : "Just take them on the suction line 3 to 6 inches from accumulator."

Which is the proper way ???


Also , will it do any good to insulate the accumulator ???
I found a post from Shamino in VR-Zone here :"they dont usually insulate a/c compressor's integrated accumulator but u shd when u run it for pc use as you will wanna run into a vaccuum or close to it, insulatin the accumulator is very important as these compressors are desinged to run high suction pressure while we are using them to ruin into vaccuums."

Yesterday i received from Hitachi the PDF file i was looking .

In page 25 i read :
"1.6 Liquid Refrigerant Return Limitations 液体制冷剂回流的限制
Liquid refrigerant level in s-tank should be lower than the top
of s-pipe in s-tank.(see chart at right)
储液器内的液面应比储液器内S 管的前端位置低。（参照右图）
There should not exist noise of the liquid refrigerant compression,
current and vibrancy increase. System can append the assistant stank
or reduce the amount of refrigerant to prevent from liquid refrigerant
compression. Refrigerant system forbid liquid refrigerant from flowing
back compressor in any case. In normal condition the overheat gas refrigerant
should flow back compressor."

What do you understand from this ? S-pipe in s-tank ? (There is no chart to check )
The accumulator has a U pipe AFAIK .

[LostInSpace278]

S-pipe= Suction pipe
S-tank= Suction line accumulator