[Kevin999]

Is anyone having any issues with Trane Compressors making a loud noise before going into thermal overload. I’ve ran three calls on new equipment we’ve installed doing this. Any help is really appreciated.

 

[R600a]

Are these scroll or reciprocating and at what point in the cycle does it make the noise and go out on overload?

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[TechmanTerry]

Operating conditions? SH at the comp? Discharge line temp?

 

[pecmsg]

Something not set up right!

 

[YingGiang]

Is anyone having any issues with Trane Compressors making a loud noise before going into thermal overload. I’ve ran three calls on new equipment we’ve installed doing this. Any help is really appreciated.

I don’t think it like power blip. I noticed it a few times when I check the SS2 float switch for water while the system running. I was not careful and cut the outdoor off momentarily. Immediately I heard the compressor making loud noise and going into overload.


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[Kevin999]

I’ve only seen the problem occur once on site.
The other two we’ve just been aware of due to customers taking videos for us.
That we are aware of, it has happened to three of our Trane Systems. One 14 SEER 5 Ton, and two 16 SEER 3 and 2.5 tons.
These are scroll compressors.
When we arrive to check the systems
Refrigerant charge is perfect
Superheat and subcool values are good.
Amp draw checks out.
On our first customer we replaced the compressor, no luck.
We went back and replaced the TXV, no luck.
We went back and flushed the entire system with r11, no luck.
We went back and replaced the entire coil with a different brand using a piston, no luck.
The system will cool just fine for a few days then it will make that noise and go into thermal overload. Once it cools back down it works just fine for a few days.
When I saw the fault happen in person the refrigerant pressures were
Suction 186 liquid 260
The thing that has us stumped is that our first two customers it happened to have not called us back in about a week because it hasn’t done it again.
I’m looking to see if we are the only ones having issues with this on Trane Products.
I do have a video of the systems making that “clicking” noise but I don’t think I’m allowed to post it since I’m new to the forum

 

[BNME8EZ]

I’ve only seen the problem occur once on site.
The other two we’ve just been aware of due to customers taking videos for us.
That we are aware of, it has happened to three of our Trane Systems. One 14 SEER 5 Ton, and two 16 SEER 3 and 2.5 tons.
These are scroll compressors.
When we arrive to check the systems
Refrigerant charge is perfect
Superheat and subcool values are good.
Amp draw checks out.
On our first customer we replaced the compressor, no luck.
We went back and replaced the TXV, no luck.
We went back and flushed the entire system with r11, no luck.
We went back and replaced the entire coil with a different brand using a piston, no luck.
The system will cool just fine for a few days then it will make that noise and go into thermal overload. Once it cools back down it works just fine for a few days.
When I saw the fault happen in person the refrigerant pressures were
Suction 186 liquid 260
The thing that has us stumped is that our first two customers it happened to have not called us back in about a week because it hasn’t done it again.
I’m looking to see if we are the only ones having issues with this on Trane Products.
I do have a video of the systems making that “clicking” noise but I don’t think I’m allowed to post it since I’m new to the forum

I am not trying to be rude but his is a long post with very little information in it to help with diagnosing your problem. The only real data is 186/260 for pressures the one time you saw it happen which are not normal pressures for a properly operating system.

As a Trane dealer for 40+ years i have not seen what you are talking about. I would love to help you figure this out but I need more info than perfect, good, checks out, etc. The pressure you list look like a system that is equalizing which would mean it stopped for a undetermined period of time. If this is what happened then rather than replacing refrigeration components time would be better spent finding out why it short cycles some times. There are ways to put tattletales in the circuit at all controls that could cause the short cycle and it would tell you which one it tripping then yo could focus on the why.

 

[VTP99]

Yeah I suspect a underlying condition.

 

[TechmanTerry]

Wow, thats a lot of stuff replaced w/o any good results.
186 loside and 260 hiside does not sound right. What was IDDB/OD ambient?
Put in a SGMI at the AHU.

 

[ehsx]

Copeland scroll compressors can be noisey when starting under low lift or inverted starts at times and can trip on discharge temp. If you have a core sense module it will tell if motor temp or discharge temp.
Never saw this until using R 410a in chillers 3-4 years ago.

Other issue on older units is t'stat or contactor chatter on start causing backwards rotation & discharge stat trip.

 

[R600a]

What kind of thermostats are on these systems that are having trouble and do they have any off-cycle delay?

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[slctech]

I have been out of the residential trade for a bit so not familiar with these particular Trane condensers or their product now. First thing that comes to mind is something inherent to your or your companies install practices. I am not thinking so much refrigerant piping or charge issues, even though the pressures you offered were vague and useless, I am thinking more on the wiring and addition of controls and or safety devices. You mentioned the float, I would make sure that in your case that you are not breaking the Y terminal to the condenser with that? A compressor does not like being stopped and then restarted like you noticed and could easily lock up mechanically under certain scenarios, a dry contact switch in series with your compressor contactor's control voltage with out some form of safety delay is asking for problems.

I would suggest breaking R to the thermostat, if that float is to trip/chatter it will knock out the thermostat and allow the thermostat to recycle, hopefully with a 5 minute anti-cycle in the thermostat. Or install a basic adjustable time delay (ICM102) in the condenser and maybe turn it to 2 minutes, so you have a bit of protection if Y is broken.

Again, I have a hard time believing lighting strikes three times in the same spot, many long time Trane guys here, as you can see, and many of us are here daily and I have not read of anything similar recently, so not seeing a trend here. Most of us have been around long enough to get a feel for what may be happening here. I believe that these compressors are being short cycled and something inherent to Trane scrolls, actually all compressors, is not liking this, at all. And to mitigate this is to make sure that you are not short cycling these compressors with an install practice or component you are all using.

I will clarify R600a's question.....What type of thermostat are you guys using? And if a powered thermostat (not battery) how are you powering it like in this specific install, and is there an anti-cycle delay offered with the thermostat, and if so is that parameter being utilized?

 

[Kevin999]

More Info When System Operating
Single Stage Scroll Ckmpressors
Line Voltage Between L1 & L2- 240v
Low Voltage- 26.1V
Compressor Amp Draw- 9.48 Amps
External Static Pressure- .78 ( I know it’s a bit high)
Blower Motor Amps- 4.5 Amps
Indoor Line Voltage- 121v
Return Air- 67 degrees
Supply Air 49 degrees
Suction- 134psi
VSAT- 47
Liquid- 362
LSAT- 109
Suction Line Temp 61
SH 13
SC 8
Liquid Line Temp 101
86 degree ambient temp
Liquid Line 3/8”
Suction Line 3/4”
We do have a safety switch on the primary drain line that cuts off R terminal
T6 pro Honeywell thermostat has a 5 minute delay.
( if power to r is lost it will take 5 minutes to kick back on to cooling mode)
Its not short cycling on a safety switch
I’ve tested drain lines to make sure they are clear.
All low voltage terminals are tight.
Inspected contractor and all looks good.
I have been working for Trane Dealers for 8 years and I’ve never encountered this problem before.
We have installed about 50 Trane Residential Units this year and we are only having issues with a handful.
We have yet to hear back from any customers, saying it has broken down again.
We contacted Trane tech support and they were no help, they advised TXV which we have already done.
I know it’s a weird situation, I have limited info as well, because when we get called back to inspect what went wrong systems work just fine.
I mainly started the post to see if anyone is encountering the same problem. If I find a solution I will make sure to keep this post updated.

 

[Kevin999]

Thanks for the reply, after reading some replies I have also been leaning towards something causing the compressor to short cycle. I just can think of any reason why. I posted some more info, and yes we have float switches that cut R terminal with a thermostat that has 5 minute delay on them. Sorry for being vague in the first post I didn’t realize it until I posted.

 

[TechmanTerry]

The room air temp is 67*F ? Supply air temp (49*F) is kinda cold for a loside 134 PSI( 47*F SST). T'stat 5 min anti short cycling only works when "R" has lost power? How was it determined that the comp was (off)in a thermal overload?. An improper lo volt connection(wire nut,crimp connector, screw, nail into lo volt wire) can cause the comp to short cycle causing the comp to reverse rotate causing the comp to scream in pain, causing the comp to go off by overload after a minute or so. What kind of drain line safety switch?

 

[BNME8EZ]

Just a thought for what it is worth. I have seen HPC in the unit have a cracked housing. It works fine except under certain conditions the crack will let the switch move enough to drop power to the contractor.

 

[Kevin999]

I just left a customers house where it did it again after two days of it cooling just fine. After manually short cycling the compressor by engaging and disengaging the contractor, the same noise occurred. So I know the problem is short cycling. After verifying terminals and wire nuts were all secure, Safety switch cuts of 24v to R terminal, And verifying thermostat has a time delay. The only reason I could narrow down to cause the compressor to short cycle is a faulty pressure switch.

 

[ehsx]

I just left a customers house where it did it again after two days of it cooling just fine. After manually short cycling the compressor by engaging and disengaging the contractor, the same noise occurred. So I know the problem is short cycling. After verifying terminals and wire nuts were all secure, Safety switch cuts of 24v to R terminal, And verifying thermostat has a time delay. The only reason I could narrow down to cause the compressor to short cycle is a faulty pressure switch.

~1992 Lennox had a problem with ss antirecycle boards. Contactor chatter could cause the compressor to run backwards if pressure had not equalized before starting. Compressors would run until tripping discharge t’stat. I would test by dragging the t’stat run wire across the terminal to make sure it would lock out on antirecycle.

 

[R600a]

I just left a customers house where it did it again after two days of it cooling just fine. After manually short cycling the compressor by engaging and disengaging the contractor, the same noise occurred. So I know the problem is short cycling. After verifying terminals and wire nuts were all secure, Safety switch cuts of 24v to R terminal, And verifying thermostat has a time delay. The only reason I could narrow down to cause the compressor to short cycle is a faulty pressure switch.

Sorry if this has already been asked but do these problem systems possibly have nest thermostats?

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[pecmsg]

Install a delay on make timer!