oil change

seraaco · Jun 29, 2009

Hi all why change oil on a refrigeration rack system by time and not after an oil test that shows oil problems?
low and medium temp R 404 tyler racks most of them, and some hussman also
so carlyle, bitzer,copeland compressors installed.
by the way the last company suggested an oil change every 6 months
POE oil by the way thanks

Dowadudda · Jun 29, 2009

I can say emphatically, that oil can break down, and not have acidic characteristics that would not show in the oil acid test. The lubricity and composition of the oil can absolutely be compromized yet not have an acidic condition. People think I am crazy, and I am no scientist, but that is what I witness in the field. Just last week I found a scrambled pump, the wrist pin was laying in the oil sump. Out of sheer curiosity I tested the oil with a oil test kit. Did not show acid. But if you looked at this fluid, you knew darn well it was not good for the system. Especially comparing it's feel and consistency with new oil out of a gallon of fresh oil.

Refrigerant oil is synthetic, so it is not petroleum based. It's a concoction of chemicals. And these chemicals separate and lose the oil like fluid it once was.

man from trane · Jun 30, 2009

Interesting. I have a customer with R-22/mineral oil in a Hussmann split rack. He does not remember when the oil was last changed, but it was more than a year. I told him it's time to change it but he is not wanting to do it. I was thinking about testing it, but maybe that's not effective. It appears darker than normal, so it may be just slightly burnt.

How do you convince a customer to change the oil yearly on R-22 low temp?

Phase Loss · Jun 30, 2009

if they are too hard headed to listen to your warnings.

loose a few compressors

but your on an island..so maybe you just gota loose one

man from trane · Jun 30, 2009

Phase Loss said:
if they are too hard headed to listen to your warnings.

loose a few compressors

but your on an island..so maybe you just gota loose one

They have 3 low temp and 3 medium. One medium looks very new. All 6 run balls out and still don't really keep up during the day. If they lose just one, it will not be good. At least mineral oil is not that pricey compared to POE.

I'm trying all morning (slow day) to find info on how often to change different oils. The compressor makers don't say, oil makers don't say, can't find much Hussmann info, it's like a secret or something. I always thought the oil test was the standard, but after what Dow said, maybe not.

jpsmith1cm · Jun 30, 2009

I think that your replacement interval is going to be a variable. I have low temp 22 racks that get annual oil changes religiously.

On the other hand, I have med and high temp racks that haven't been done ever. Oil doesn't test bad, doesn't look bad or smell bad. I'm not changing it.

We use OF-303 filters. This seems to help a LOT in keeping the particulates out of the oil.

rocket · Jul 1, 2009

customer was told it's time for annual oil change on his Carrier Compressors, customer called Carrier which said "unless the oill is bad, damaged from over heating or acid, there is no need to change it" and refered customer to www.carlylecompressor.com. The contractor lost this account. Oil test kits usually for acid only, you also need to inspect the oil, is it thin=it's bad, is it brown=it's bad,does it smell=it's bad.

K_Neil · Jul 1, 2009

Is there a viscosity test or field inspection only?
Just wondering.

rocket · Jul 1, 2009

Is there a viscosity test or field inspection only?

that can be done, but too expensive, normally you can feel it if you touch a sample, if it pours like water - no good. Gritty - no good, Brown in collor - no good. 98% of time just touching it works. Overheating causes thinning and/or brown color.

oil change

seraaco

Dowadudda

man from trane

Phase Loss

man from trane

jpsmith1cm

rocket

K_Neil

rocket

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