Low ambient AC fault

[RADO]

I have a problem with a Carrier 38AH-055 R22 AC condensing unit that is operating as a process AC.
Evaporator has to cool an electrical switchroom with an ambient aprox 21C to be maintained.
Outside the ambient is dropping to 5C. Problem is the crankcase heater dosnt seem to be warming the oil enough to stop foaming and slugging on startup.
Not being used to low ambients has anyone come across the problem of the cranckcase heater not providing enough heat?
Carrier manual says operation is good down to -30C (with cond fan controller)
I also suspect the suction line may be acumulating liquid.
cheers

[chris96]

Not sure of the model on this unit, it is a chiller is'nt it?

Have you took the temp of the actual heater, I would expect around or above 120 C. Also have you checked amp draw?

Chris.

[scottishladx]

I have a problem with a Carrier 38AH-055 R22 AC condensing unit that is operating as a process AC.
Evaporator has to cool an electrical switchroom with an ambient aprox 21C to be maintained.
Outside the ambient is dropping to 5C. Problem is the crankcase heater dosnt seem to be warming the oil enough to stop foaming and slugging on startup.
Not being used to low ambients has anyone come across the problem of the cranckcase heater not providing enough heat?
Carrier manual says operation is good down to -30C (with cond fan controller)
I also suspect the suction line may be acumulating liquid.
cheers


Put a jacket on it :p

[Haden4ever]

Have you checked the superheat? slight liquid return can have dramatic cooling effects, CC heaters normally either work or don't, although cold spots are possible

[sinewave]

Are you suffering from low RH in the switch room which is contributing/causing probs?