Quick and Basic Troubleshooting

[Icehouse]

Like Repair Man said, long winded. 

[whirlpooltech]

I will not troubleshoot when I am tired, upset, angry,
or hungry.

 

Good stuff, keep posting. 

[Repair-man]

I have one problem with it...

You then should perform an efficiency test.
1. Remove cover from low pressure control and
jumper it out.
2. Front seat the suction service valve.
3. The compressor should pull into a vacuum

In order for the unit to pull a vacuum, the discharge  valve should be backseated not the suction. In fact, the system should never be started with the suction valve shut off.

[Icehouse]

Even General Electric and Whirlpool technicians manuals describe this test. In place of a suction service valve they advise you to pinch off the suction line and using the "Robin Air" pinch off tool, reshape the lines.
These are notes compiled from material used in teaching, so I research everything I write. All that has to happen is someone getting hurt or hurting someones equipment and wham "Lawsuit".

[Repair-man]

Well, now you are talking about refrigerators and not central A/C...


make up you mind

there are no low side controls on a fridge and I'm sure there is some sort of test like this for fridges, not that we practice this as techs. However, I routinely check the integrity of the reed valve on A/c compressors by closing off the liquid line valves and letting the unit pump down to about +5 psi. If it holds after shutting the unit off, the valves are fine.

[Icehouse]

  You sound like some of the "experts" that call me.
Depending on the application there are "low pressure" controls on refrigerators as well as air conditioners.
I worked on everything from 4,000 BTU window units in homes as well as 949 ton "Centrifugal Chillers" at JFK International Airport to gas fired absorption units on Wall Street.

[Repair-man]

I am one of the experts, but I doubt I'd need to call you for anything but maybe to go for a cold one

As a past Rheem, Carrier and Goodman dealer, I can attest that the warranties clearly state that they will be voided if the unit is run with the suction line closed.

That's about all I got to say on the matter.

[Icehouse]

I am one of the experts, but I doubt I'd need to call you for anything but maybe to go for a cold one

As a past Rheem, Carrier and Goodman dealer, I can attest that the warranties clearly state that they will be voided if the unit is run with the suction line closed.

That's about all I got to say on the matter.

Say Jim, don't get your feathers ruffled, but if you ever read "Carrier's" training manuals the compressor efficiency test I described is in there. But again like you said you are an EXPERT.

[Repair-man]

I keep my feathers numbered for just such an occasion, suh!  

and BTW, according to R.S.E.S., I was an expert back then too ....

[whirlpooltech]

 

[Repair-man]

yup..

[Icehouse]

Well I must appologize when necessary.  Carrier informed me that the do not recognize this method for Air Conditioning. As for Refrigeration, they are no longer involved. Seems they just shut that part down (Tyler) and laid everyone off.  

[Icehouse]

This is from "Carrier's" original handbook 1968.
To test small hermetic and semi-hermetic compressors used for medium and low temperature applications, the following method can be used to test for internal valve leakage.

1. Attach a low pressure gauge to the suction line service port.

2. Close the compressor off from the low side of the system by front seating the suction service valve.

3. Run the compressor for two minutes.

4. Turn off the compressor and observe the reading.

The compressor should have pulled down to at least 16 inches (410 mm) of Hg. If the vacuum reading starts weakening toward 10 inches (254 mm) of Hg vacuum, the discharge valves of the compressor may be leaking and will probably need to be replaced. If the compressor doesn't pull a vacuum below 16 inches Hg, the suction valves are weakening and may need to be replaced. If the compressor is welded or hermetically sealed and these conditions exist, a new compressor is the only possible remedy.

[Repair-man]

I keep forgetting how old you and I are...well, you mainly. Those older compressors were built differently than these pieces o' crap that pass for compressors today. I'm sure Carrier changed their stance later down the road when the manufacturing process changed. We're both right....no need to appologize.

[Icehouse]

  Age is nothing more than a number, along with wisdom gained.