Condenser not Heating

[johanine1]

I am new in the refrigeration trade, barely 1 week. I need some help on the possible causes of the problem I encountered in the freezer I was working on. 1) Evaporator is not cooling. There was no heat coming coming out of the condenser. However, Compressor is running. 2) How to isolate/make a jumper on a LP/HP pressure switch in order to know if the problem is the pressure switch and not the compressor? Many thanks.

[Brian_UK]

Pressure switches do not do any work it is only the compressor that moves the refrigerant around.

Do you have any access ports on the pipework to enable system pressures/temperatures to be measured?

[andywill]

Sounds pretty obvious from your description that either there is no gas in the system or the compressor is not pumping. Fit high and low side gauges to obtain pressure readings and post your findings back here, I'm sure you will find your answer. If the system has no gas in it then firstly it should not be running and secondly you have a leak(s) which you must locate and repair.

[nh3wizard]

I dont know how to put this without sounding like an arshole; but have you any kind of training at all?

[jdunc2301]

Firstly... If the Evaporator is not getting cold and the condenser is not getting warm, no refrigeration is taking place. Very common and may well be a poor pumping compressor or SOG....(short of gas).

The Lp/Hp Switch this does not directly affect the movement of refrigerant, the live feed for the compressor or compressor contactor will be wired through the LP/HP switch, if tripped H/P or L/P compressor will not run.

If the compresor is running then your deffinately not tripped H/P, there may not be a L/P switch fitted just double check....

This would indicate a buggered compressor...not pumping!

Without being there we cant provide diagnosis, stick some gauges on the system and see what she doing, check for positive pressure and your temperatures including L/P H/P set points on the pressure switch.


IF YOUR ONLY IN THE GAME 1 WEEK THE ENGINEER TEACHING YOU SHOULD BE DOING THIS IT ALL TAKES TIME TO LEARN

[aj]

i think you should leave well alone before you hurt yourself, thats pretty basic refrigeration.

[M.Amer]

charge some refrigerant n notice air out
temp-see site glass if there is notice if bubbling try simple pressure test mentioned by a guy here

[jdunc2301]

You need to accertain wether you have a knackered compressor:

Gauges showing positive pressure? -------Test operation of compressor, if no movement in pressure compressor (possibly) not pumping.

Compressor runs------ pressures on gauges drops into a vaccum and no cooling on EVP or heat on COND (possibly) system blockage or SOG (short on gas) , check filter drier, expansion device (TEV, Capillary)

Gauges showing NO pressure?------- Carry out a good OFN (oxygen free nitrogen) pressure test, look for pressure drop, check all suspect joints, poorly brazed joints, oil stained areas. With Leak detection spray or prefered method of leak testing.

If leak is found and component is replaceable or the leak is repairable, then do so.

Carry out another pressure test using OFN, and leave for a good period of time and look for pressure drop. If all seems ok, pull a vaccum on the system and recharge to rating plate.

Run the unit and look for cooling on the EVP and heat at the COND, compressor may have failed if the unit has lost all its charge and no L/P protection has been fitted.
I would also add some leak detection dye, if the leak was not found.

This is the sort of thought process you should be going through, there are several shortcuts that me and other A/C & R Guys will do to shorten the job and get a diagnosis quicker.

charge some refrigerant n notice air out
temp-see site glass if there is notice if bubbling try simple pressure test mentioned by a guy here

No......
If the condenser or any pipes have a split or fracture you will merely be venting refrigerant to the atmosphere, this is why a good pressure test with OFN happens first. Just charging the system makes a joke of all the safe handling certificates and paperwork we have to fill out.

good luck