Compressor Icing

[dsiyalom]

What would be the cause(s) of compressor icing ? This happens when the load in the cold room increases. Infact the cold room together with the compressor has been functioning for 10 years without any problem. But the problem started occurring this year. Is this an expansion valve problem? Or some impurity in the system?

Any help on the subject will be appreciated.

[Emmett]

Need more information.
(1) What type of load and how is it added?
(2) refrigerant type
(3) Pressures/temperatures/superheat/subcool
(4)evap fan operation
(5) defrost operation
(6) operating temperatures
and any other information/observations you think would be usefull in troubleshooting this problem.

Possibly low on charge or air flow issue with evap these are common causes.

[FRIDGE]

hi,

if the system has been operating and the use/ application of the system hasn't changed for ten years and the problem only occurred recently then a few suggestions:

without the knowing the operating temps and pressures and problem occurs at high load:

- check for correct air flow across evaporator ( sometimes users block off return air flow with the food/stock)
- check expansion valve phial is clean, and secured in the correct location on evap outlet. ( is insulation damaged)
- ensure all evaporator fans are working
- ensure evaporator coil is clean
- check refrigerant charge ( if short of refrigerant, at high load system will be unable or struggle to cope, then compressor runs continuously and causes icing of suction line and compressor)

note- once a TEV has been set and working, do not adjust.

if you need more help please provide more info on the application and type of system i.e what they storing in there, refrigerant, size of system, how many evaporators etc.

[ulster_man]

1st.. Check your gas level... has it a clear sightglass?
If so... check and adjust your superheat because that will be your problem, expansions valves close down when the temperature on suction gets colder and colder, sounds like your valve is not closing.
If it been operating for 10 years + then advise to change the expansion valve and orifice altogether

[dsiyalom]

Dear Emmett , Fridge and Ulster_man,

I thank you all for all the great recommendations . The customer has cleaned the evap coils (they were nearly clogged) and changed the TEV and the icing problem disappeared. The customer also had to add slightly more refriferant to the system.

I wish you all the best !!!

Dan


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