R-410A heat pump compressors 'de-coupling' during heat operation

[thermojohn]

Hi - Been a while since I posted here.

I am an HVAC contractor and am noticing a pattern with several R-410A compressors in (less than one year old) heat pump systems we've installed. After a cold night, I'll get a call from someone saying their outside unit is noisey and system is not heating.

What I see when I arrive is the compressor is running, but not pumping as pressures are equalized. Somehow the motor has 'de-coupled' from the mechanical assembly internally. It is not the same internal relief sound normally heard in R-22 based compressors.

Turning off the compressor for a day gives it time to cool down (or catch up with itself), then it operates normally again.

Anyone else experienced this? What causes this? Reversing valve sticking in mid-position? Long defrost cycle resulting in high head pressure?

BTW, these are Goodman units with Copeland scrolls. So far, have only seen this with 2.5 ton units.

[SBKold]

probably sticking rev valve

[seanddd]

There's a Goodman recall on this, that might be it.

[thermojohn]

There's a Goodman recall on this, that might be it.

Really? What kind of recall?

[seanddd]

SR-036 and SR-041. You can search for old discussion
threads in this forum.

Really? What kind of recall?

[tlb]

had same kind of problems RV's been sticking.goodman did have recall on "Danun" valves I think i got name right they are junk.had one just month ago screwed on gauges with compressor running pressures were equal and compressor sounded rough. got to checking and the valve was stuck

[VTP99]

[QUOTE=thermojohn;9151851] Somehow the motor has 'de-coupled' from the mechanical assembly internally. Copeland scrolls.

I don't think that is possible and then work again.

[thermojohn]

OK - Now we're getting somewhere. Danged ol' Chinese reversing valves. Looks like the imprint of a flower embossed on the valve. Don't know the brand.

Thank you for responding everyone. Anyone else have any problems with these?

[just_opinion]

OK - Now we're getting somewhere. Danged ol' Chinese reversing valves. Looks like the imprint of a flower embossed on the valve. Don't know the brand.

Thank you for responding everyone. Anyone else have any problems with these?

Before we are all shooting down those chinese this chinese that R-valve, read EVERY word on the side of the compressor. The answer is there. Too many compressor and R-valve have been changed for no reason. Except it does not speak the native tongue.

Sorry, I cannot give further information. I have to treat you as DYI.

[thermojohn]

I don't think that is possible and then work again.

I hear ya. I've experienced this twice, though. Sounds like only the motor is running (like a sheared shaft). It might have been operating through the 'stuck in mid position' valve, but usually I'll hear the whooshing sound of gas going through the valve if it is stuck in mid position. That was not happening the times I've experienced this. Give the compressor time to cool, and restart it and it operates like nothing ever happened.

I do not know how the shaft is connected to the motor internally. I was thinking like a magnetic drive to protect the compressor from high pressure or something. Only seen this with R-410 compressor and not R-22 types.

I'm all ears if you know something about this.

[seanddd]

internal relief?

I hear ya. I've experienced this twice, though. Sounds like only the motor is running (like a sheared shaft). It might have been operating through the 'stuck in mid position' valve, but usually I'll hear the whooshing sound of gas going through the valve if it is stuck in mid position. That was not happening the times I've experienced this. Give the compressor time to cool, and restart it and it operates like nothing ever happened.

I do not know how the shaft is connected to the motor internally. I was thinking like a magnetic drive to protect the compressor from high pressure or something. Only seen this with R-410 compressor and not R-22 types.

I'm all ears if you know something about this.

[thermojohn]

Before we are all shooting down those chinese this chinese that R-valve, read EVERY word on the side of the compressor. The answer is there. Too many compressor and R-valve have been changed for no reason. Except it does not speak the native tongue.

Sorry, I cannot give further information. I have to treat you as DYI.

I am a licensed contractor and not DIY. Do I need to post in the pro section to get the real scoop? It has been a long time since I've posted here at HVAC Talk. A lot of changes have taken place here since.

[BaldLoonie]

You've got the post count for sure, so apply for pro membership and it gives you access to the educational forum as well.

[thermojohn]

OK, will do. Again, thanks for the input everyone on this.

[Kevin O'Neill]

Lennox has had the same problem. Copeland 1.5 and 2 ton scrolls on R410a. They have switched to another compressor manufacturer for their small scrolls.

[VTP99]

.

[VTP99]

Lennox has had the same problem. Copeland 1.5 and 2 ton scrolls on R410a. They have switched to another compressor manufacturer for their small scrolls.

What is the problem with the compressors ?

[SBKold]

I wanna know too.

What is reading the side of compressor going to do?

We are not talking big scrolls here with that ASTS thing.

[thermojohn]

Lennox has had the same problem. Copeland 1.5 and 2 ton scrolls on R410a. They have switched to another compressor manufacturer for their small scrolls.

Interesting.... Here's something else I found out today regarding this unit:

The original compressor in this unit is a ZP25K5E-PFV-130
The replacement compressor for warranty is a ZP26K3E-PFV-930

I wonder what the difference is in the make-up internally? Other than 1,000 BTU nominal increase in capacity?

So is it the compressor or reversing valve? I'm not a parts changer until I verify the failure of the component. This situation I have not seen 'fail before my eyes' yet.

[Kevin O'Neill]

The compressors get noisy and stop pumping. Only happens in heat mode and below 30 degrees outside. Turning it off and waiting a few hours sometimes fixes it....for a while.

Jumping the defrost board for soft changeover helps sometimes as well.

Permanent cure, replace with another brand of compressor.