Argo AEI1G 42 EMX, Technical Data & Service Manual

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15
Defrost valve
Defrost valve is used to run the hot gas byapass defrost cycle.
Defrost valve is always closed during cooling mode.
Defrost valve is normally closed in heating mode and it opens only during hot gas bypass defrost cycles.
When open, part of the hot gas from the discharge of the compressor is directly injected into the
outdoor heat exchanger. This will defrost the outdoor coil while keeping the system running in heating
mode (no need to reverse the cycle).
Crankcase heater
Crankcase heater around the compressor is used to prevent refrigerant migration and mixing with
crankcase oil when the unit is off, and to prevent condensation of refrigerant in the crankcase of the
compressor. The crankcase heater keeps refrigerant at a temperature higher than the coldest part of the
system.
Crankcase heater is activated if the following conditions are met:
-
Compressor is stopped
-
OAT il lower than 5°C
-
Difference between CDT and OAT is lower than 18,5°C
When crankcase is active, it will be deactivated if one of the following condition is met:
-
Compressor starts
-
OAT increases above 5°C
-
Difference between CDT and OAT is higher than 21,5°C
Drip tray heater (built-in) and condensation water heater (accessory)
The drip tray heater and the condensation water heater prevent condensation freezing on the drip tray
and the condensation water pipe.
The heaters are activated if the system is in heating mode and one of the following conditions is met:
-
OAT il lower than 0°C
-
Defrost is active
-
Less than 5 minutes have passed since last defrost
When heaters are active, they will be deactivated if one of the following condition is met:
-
OAT is higher than 2°C
-
Defrost is not active and more than 5 minutes have passed since last defrost