Ever Hear of Copper Plating Inside the Compressor?


First off, I want to thank Ulises Palacios for taking these photos. He is in the habit of cutting open the compressors he replaces to see why they failed (when possible). I think that's pretty boss.

So, why would the compressor have copper plating on the inside? They certainly aren't manufactured that way.

The short answer is that acids inside the system can eat away at the copper and brass components in the system. The copper is then deposited in the high pressure/temperature environment of the compressor.

Why does this happen?

The presence of any acids in the system can cause this to occur, but the most likely causes are the combination of air and moisture reacting with the refrigerant oil (most prevalently POE) to create an environment in which the copper is dissolved internally and redeposited on the steel in the compressor.

The result inside the compressor is reduced clearances and ultimately locking, overheating, and even short circuits if the mechanical failure results in winding damage, as is fairly common.

So, for a technician, we can ensure that we are properly evacuating the system and installing appropriate filter driers to reduce or eliminate the presence of air and moisture.

—Bryan

P.S. – For an in-depth analysis of a study on copper plating in compressors, you can read a literature search here.

Related Tech Tips

What is an ERV?
This quick tip was written by Daniel Andersen in the HVAC School Group. Daniel was one of my early encouragements to make the podcast, even though he refuses to come on himself. Thanks, Daniel! ERV – What is it?  An energy recovery ventilator allows fresh air from outside to be introduced into the conditioned space […]
Read more
Ain't No Fooling With Free Cooling (Tales of the Economizer)
This article was written by Gary McCreadie from “HVAC know it all.” You can learn more about Gary and his tips and growing community on Facebook and LinkedIn. What is an economizer?  Simply put, it is a mechanical device designed to reduce energy consumption, whether it be fuel, electricity, or other. According to Wikipedia, the first […]
Read more
Leak Detector Maintenance and Care
A good leak detector is a big investment and one of the more important tools a tech has on the truck. I've had the same leak detector for years, and I've replaced everything on it, from sensors to pumps to the probe. And no, the one shown above isn't mine. One thing that I have […]
Read more

One response to “Ever Hear of Copper Plating Inside the Compressor?”

Leave a Reply

Your email address will not be published.

This site uses Akismet to reduce spam. Learn how your comment data is processed.

loading

To continue you need to agree to our terms.

The HVAC School site, podcast and daily tech tips
Made possible by Generous support from