Copeland CR Shell Leak

[icemeister]

One of my C-Stores calls and says the walk-in cooler is at 50ºF so I go check it out. I get to the roof and find the base of the 5 HP condensing unit and the roof deck below covered with oil and the unit short cycling due to loss of refrigerant.

I find a small round crack in the shell about 1/3 of the way up the side and it's bubbling away leaking R22 and oil. It's at a factory spot weld for the internal motor/compressor mounting bracket. I'd never seen this before but now it's the second CR I've seen in three months at another C-Store with the same problem. New compressor time again.

The interesting part is that both failures were on system where both condenser fan motors were replaced recently....like within six months. Both units were cycling on the high pressure control for I don't know how long before I got there. My guess is that the constant violent banging on and off fatigued the metal at the weld and it just broke loose.....they really do jump a bit when stopping at 350#+ discharge pressure.

[hem057]

seen them with rust hole through the can before, but then they were old units.... never like the one you mentioned.

[jeep6275]

i have had two also. one on a lennox package unit and one on a trane package unit. both 5 tons. i have yet to see any in medium temp.
oh by the way the package units were used and abused and very likely running high head.

[basser]

Ice,

You are correct here. 4½ & 5 hp are the most prone to this. Usually this happens to three phase compressors, but occasionally you will see it on single phase, this is because of the starting torque. There is always a possibility of a defective weld, but this problem comes from short cycling and the constant banging of off and on.

Basser

[icemeister]

Thanks for the confirmation.

Yep, both were 3 phase. The latest a CRN5-0500-TF5 (1991) and the previous one a CRJ3-0300-TF5 (1997).

If they were single the start cap likely would have blown up before any such damage could happen.

The manager at Baker Bros said he's only seen one other like these about five years ago. It was a first (and second) time for me.

[icemeister]

I finally got around to downloading the camera so I could post this picture of the CRN5-0500 shell leak:



You can clearly see the small crack just above the spot weld.

[~L~]

1991 and 1997

Did the owner of your Cstore ask for factory warranty replacement?

[icemeister]

No BS from either of them.....and both are Indian. The one with the '97 did think that I'd just installed that unit.

BTW, Cute name.

[~L~]

U R lucky my friend

[k-fridge]

Never seen cracks there, only at the feet and where lines go in. Copeland needs to know about this.

I have brazed cracks in the shell up with 45% before but I don't know if it would work in that spot or not.

[thegoodhumorman]

(..in my best Ahnold shvazenegger voice)...

"Vat iz vrong viz it- I haff only hitten it viz mein hammer a few times to unstick it- now you tellin me zat it leaks ..? Hah! It iz obviouzly defective!

[theycallmethefireman]

we run across that a couple of years ago. however, we did not change the compressor, heated the shell and applied 56% silver topped it with 15%.

If you are asking yourself why we did this, which I am sure everyone of you are......reason is he is one of the many who operates a convenience store and sends money over to his other arab blower uppers and he always whined and moaned over the bill when it comes time to pay

[forged alloy]

Copeland knows about the problem. I took a factory Rep. out to a site where we lost two over a two year time period.

They sampled me a scroll compressor N/C to replace it.

I'm sure they have fixed it since then. Haven't seen anything new have a similar problem.