What is this mess?

Hi there,

Please have a look at the attached pictures.

These are some hermetic compressors which have some kind of contamination inside.

My first reaction was: synthetic oil contamination with moisture.

Any ideas?

Cheers

crumbled bits of filter material?

Hi Lana.
At a guess it may be either where the lacquer or resin.
From within the windings has reacted to either excessive heat.
possibly during a burn out!
Another option is related to the particular refrigerant being used, you don't say what they where.

It is difficult to see what the contamination "feels" like.
But I see something like this often in semi-hermetic recips.
Where you have had large increases of heat and Mineral Oils!
Cheers Grizzly

Looks very 'carbon-like'.

As Grizzly mentioned above - heat & mineral oils.

To get such a lot of granular carbon, I'd guess the temps would have to have gone up pretty far.

Copeland AE-1263-R3 / 1 April, 1993:
"Most refrigeration oils will start to break down or carbonize at 325'F (162.78'C) even in a contaminant free system. In a typical system (which is seldom contaminant free) chemical reactions can occur at lower temperatures."

I wonder if dye, or an additive was used?

Thanks everybody,

The refrigerant is (or supposed to be) R134a with synthetic oil.

Here we have many problems with counterfeit or fake equipment and refrigerants. God knows whether the compressor was for R12 with mineral oil then the user used R134a or else???????

The black stuff there, feels like powder (now it is dry but at the time of opening it was like a gum or tar, oily.

I have seen compressors which was subjected to very high temperatures because of lack of refrigerant (Low LP) but it was not like this.

Cheers

The windings don't look burnt, from the pictures, its odd how the stuff only seems to be on the rotor, i wonder if it is ferous/magnetic?

I had a bottle of R134a years ago the was contaminated with water and a black carbon like powder, i think either something had gone wrong at the bottling plant or someone had used the bottle as a recovery one....

ive found similar stuff in a couple of rack systems drier cores shells,the cores where still intact.could only put it down to moisture.as some mechanics pump down to replace cores they dont melt frosting or heat piping to stop ingress of moisture at that point isolating bulk of moisture and not completely contaminating the system,i think.

Thanks everybody.

Any other ideas?

Cheers

looks like a coal fired system,:D as suggested its looking like carbon,maybe it is contaminated refrigerant reacting with the oil or has the system had a split evaporator and pulled a load of crap in.:eek:

Residuals of machining of s&t bundles or condensers/evaporators?

What does it/did it smell like when you opened the compressor?

To me it also looks like a burn out of some kind. Yes, the windings look intact, but that is only what we can see from the surface. Who's to say that the internal parts of the windings, and those out of view are not burned to a crisp?

It could be that there are inferior or fake components in the system that can't stand up to normal operating conditions....

Silica gel filter + oil sludge resulting in granules ?

i had something similar to this when the compressor manufacturer put the wrong oil in a compressor, even the sightglass was black inside. they replaced the condensing unit and paid for my time but i never found out exactly what the problem was

look what i found !:confused:
strange thing the compressor was still up and running (copper plating)
large sh , high compr temp air inside.... ect

I would guess that is copper oxide flakes from welding
large copper pipes without purging with nitrogen during
welding as the windings look normal.
I have troubleshot comps that started severe
short cycling on the low pressure control and found
the screen beneath the suction service valve completely
plugged with that black junk but if the screen had
ruptured it would have gone into the compressor all
because they did not purge with nitrogen during welding on a new job.
If these comps shown have no suction screen then everything could go right to the motor cavity or the screen might have ruptured releasing a large charge of crap.
I have also had suction screens plug up with copper
oxide when changing 20 year old sytems from R-12
to R-134 as the crap was already there but never
broke loose until the new POE oil and R-134 started
cleaning the piping inside and it usually started screwing up at quiting time (Never fails)
POE really breaks loose all the old grease as you can
clean all the old grease off your guage hoses
I might ad that if the suction screen plugs up with this
copper oxide the compressor may get mis-diagnosed
as being a failure because of low capacity or running
unloaded with the suction gauge hooked to the suction
service valve showing high back pressure.
The only way to check for a plugged suction screen
is to install another guage on the crankcase or low
side of the head and compare to the suction line guage
You could go broke putting new compressors on the same dirty suction line if the screens are plugging up
Inline suction filters will catch the crap but are not always
required or allowed by mfgs or the line size is too large
and sometimes financial limits don't allow nitrogen or suction filters.
I hope I have helped you