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View Full Version : I wish my sidekick wouldn't go on holiday!



eggs
10-12-2004, 12:32 AM
As some of you know, i am an a/c, ventilation type of guy more orientated to the installation, design and business side of things.
My sidekick, the technical, refrigeration, trouble shooting, servicing fella has gone for his annual 6 weeks in his homeland (india).
So here i am left, doing all our callouts with no backup.

Today i got one of those "my fridge isn't working can you come and fix it?"

Anyway i went along with one of the labourers, had a look, tried my limited knowledge of refrigeration trouble shooting and found the problem. The compressor down to earth.
Off i went feeling chuffed with myself, when the labourer started pecking my head with questions i couldn't answer.

can you please help me?

Q1) why did you get a shock of that capacitor? can you not dischage it before you touch it?
A1)**** off

Q2) why do two same compressors have different resistances across the windings. Working one 15, 12 & 3. Broken one 6, 2 & 1
A2)Any more questions and your walking home.

i know these are trivial to some of you, but servicing and fixing ain't my thing, that is what my partner does and he's about 2500 miles away.

My last questions are.
When i take out that compressor on tuesday, i'm going to cut her open and have a look inside (to educate the labourers, and no other reason, honest! because i know all about them, not)

What precautions must i take? and whats the best way to do it?

cheers

eggs

Abe
10-12-2004, 01:09 AM
What precautions must i take? and whats the best way to do it?

eggs

Take precautions not to send the " real boss" on holiday

Abe
10-12-2004, 01:10 AM
Ok sorry, I know that was a " naff" reply.........
I couldnt resist it.................

Now what was the question again ????

By the way, thx a million for the info u sent...........Im chewing on it......

eggs
10-12-2004, 01:19 AM
speaking of cheap gear.
i was chatting to a customer today, who is looking to start importing "Arneg" multi deck cabinets. obviously needs people to buy them. i will keep you posted as i know more.

cheers

eggs

Brian_UK
10-12-2004, 01:49 PM
When i take out that compressor on tuesday, i'm going to cut her open and have a look inside
That should have got your secretary worried :D

Seriously though, I'm assuming that it is a small hermetic compressor here; drill a hole in the bottom of the compressor and allow the oil to drain out - dispose off thoughtfully. Also note how much oil came out so that you can compare with the original quantity.

To open the compressor I believe the best way is to use an angle grinder on the welded seam around the waistline of the compressor.

Usual cautions:- Oil contamination of yourself, setting fire to the oil when grinding, refrigerant remaining in oil will froth if can shaken.

Compressor motors are often just suspended on springs so if you turn it over the guts can fall out, generally on your foot.

Good luck grasshopper your training session. :cool:

chemi-cool
10-12-2004, 02:35 PM
Hi Brian,


Compressor motors are often just suspended on springs

No, the dicharge line is brazed inside before the two parts of the outer shell are welded.

I have this habit of cutting open every compressor over 2hp that I change, you learn a lot of what went wrong when inspecting the remains.

Chemi :)

Abe
10-12-2004, 09:16 PM
Chem

Spill your secret ( if its not classified) how you open up the baby !!!

Ivbe never done it me self, but admire guys who do !!!

Eggs...........Youre a brave man to want to try

chemi-cool
10-12-2004, 09:34 PM
OK Abe,

No big deal really.
As Brian said, get rid of the oil into a clean bucket so you can inspect it for metal particles.
It can be done by drilling a hole at the bottom or tip it on the side with the suction down wards.

Once you get the oil out, using the biggest angel grinding you can lay your hands on and cut it carefully just above the welding line.
When done, use the torch or pipe cutter to disconnect the discharge line.
Now it opens like an egg.

you can use the shell for a vase if you like but make sure to look inside and see the cause for the problem: broken piston, burned winding, acidic oil, broken shaft or broken balancing spring.

Tells you a lot about the way the system was working and maintained.

Maybe I will show you when I come over.

Chemi :)

eggs
11-12-2004, 12:11 AM
aiyub. i'm not brave, i just have to save face. you know,educate the spanner passers, while the spanner mans on his jolly's.
Why can't i just say "i don't know?"
with any luck another job will come along for tuesday afternoon and i can just pretend we don't have time.

cheers

eggs

RogGoetsch
11-12-2004, 12:56 AM
What precautions must i take? and whats the best way to do it?


With an internal short to ground, you can expect the oil to be acidic. If someone kept resetting the breaker, it can be dangerously acidic. Hydrofluoric acid is what I was told was the formed during a burn-out in the presence of refrigerant. Supposed to be pretty nasty stuff. Don't get it on you.

Rog

chemi-cool
11-12-2004, 08:56 AM
Yes Rog,

Nasty stuff acidic oil. Thats why its important to empty the oil before you cut it open.


Chemi :)

chemi-cool
11-12-2004, 12:12 PM
Thanks for the tip.
will do it next time. :)

Chemi

Superheatman
11-12-2004, 12:13 PM
Yes Rog,

Nasty stuff acidic oil. Thats why its important to empty the oil before you cut it open.


Chemi :)

Hi all...over the years I have cut open many pots and torn down and rebuilt most things ..up to two stage centrifs anyway..another couple of things to look for are tide marks around the sump which can give an indication of slugging refrigerant through the compressor ....and coppering of steel parts which is an indication of moisture in the system...best wishes all...Superheatman.