Investigating Compressor Failures

We have several Trane Voyager units on our retail store rooftop. They were installed in 2002. Since then we have had a very high compressor failure rate. High enough that we pressed the issue w/Trane and they agreed to install crankcase heaters on all of the compressors that hadn't failed. This retro worked for a couple of years and now we have another failure. I have heard rumblings that this particular model of Voyager has been re-designed, which implies there was something wrong with it. I am trying to search for information that supports this supposition. I am concerned we will continue to get hit with the cost of compressor replacement as long as we have this model on our rooftop. Can you help/advise??

LD in Oregon

Have a Preventive Maintenece program that includes power washing the condenser coils.

We have PMs in place including the coil cleaning.

Your situation is worthy of having some "smart guys" come in and do a thorough investigation, this is expensive for you!

Guest#2 said coil cleaning. Hey, we mean REALLY cleaning. Some of those rooftop units actually need the cabinet taken apart and the double layered condenser spread apart like 2 clamshells and cleaned in between them! Spraying from the outside doesn't do it!

Power quality issues can certainly do it. Inadequate airflow on the indoor side can also eventually cause troubles. If the HVAC service company is the same, try someone else just once. Make sure there are time delays for the compressors. Make sure the power wiring isn't slightly undersized. Always check and replace the contactors often, they're really cheap these days. More compressors are lost to blown fan capacitors than anything else I can think of.

Have someone fill out a complete survey with all pressures, temperatures and voltage-current draws etc. recorded. Determine the system's CFM flow and do a performance check. Make sure the economizer (if present) is working properly. If working in low ambient for cooling, use a Hoffman or equivalent head control that VARY's the fan speed, not an ON-OFF fan control, they're junk. Pull the cover off the compressor terminal and just gently try to wiggle the terminals for tightness, sometimes you'll find a discolored wire just getting ready to burn off. These have to be TIGHT!

I think MOST premature compressor failures are preventable if someone cared just a little to do some simple checklist items.

Thank you for your suggestions. I am talking with a consultant about just such a review.

I am still questioning the equipment itself. We have older model Tranes on our other store and have never had a comparable issue (one failure after another in rapid succession).

Lillian

I agree!

W/proper PM's, compressors can (and some do) last 30yrs.

We installed 2 - Trane model YCD300C3LAG, 25 ton units on a church in Oakland, Ca. in 2002, and all 4 compressors have failed. Do you think the church is p___sed? If you think this is a co-incidence, then I have some land to sell you in Florida.

A friend in California

P.S. As they say in the vernacular: This is, like, a CHURCH, like, only used on Sundays by little old ladies, like, you know.

I would be interested in knowing more particulars. When did the units get installed, were they new? Were they warranteed? What do you think caused the failure? Your own credentials, etc.

thank you!

Lillian

The units were installed in 2002. Evidently there is only a one year warranty on the compressors. Oakland, Ca. is in a very temperate zone with temperature rarely exceeding 85 deg., so high head pressure is not normally a concern. This is a church so the units do not operate often. I gathered from the web that Trane had a bad batch of compressor. I have a degree in Mech. Engr. and have been in the HVAC business for 35 years.

Hugh

You said, "I gather from the web that Trane had a bad batch of compressor." Where did you find that information?

thank you,

Lillian

Hugh:

URGENT!

Re: your comments. Can we talk? Please send private e-address, or whatever you're okay with.

illian