Fan Cycling During Compressor Off Cycle; Defrost On Demand - Danfoss ERC 21 Series User Manual

Electronic refrigeration control, type ERC 21X
Figure 8: Night mode

Fan cycling during compressor OFF cycle

During compressor OFF cycle controller will run the fan with defined duty cycle to maintain uniform temperature
and delay the need of compressor switching ON.
Figure 9: Fan cycle
Fan ON Fan OFF
cycle cycle

Defrost on Demand

This feature records the evaporator temperature when it is clean and constantly monitors the compares that at
every compressor cut outs. If the evaporator temperature goes below the recorded temperature by the value set in
parameter d30 before the configured defrost interval, it will trigger defrost immediately.
• This function can only be used in 1:1 systems.
• This function is disabled when the parameter "d30" is set to 20.
• Defrost on demand is triggered only if the time since the last defrost session has ended is greater than ¼ of the
defrost interval or 2 hours whichever is lesser.
• Defrost doesn't start by this method during the following scenarios.
◦ Pull down mode
◦ Night mode
◦ Main switch in DI or main switch in Menu is in OFF position
◦ Manual control mode
◦ Evaporator temperature greater than 0 °C.
© Danfoss | Climate Solutions | 2023.01
Thermostat cut in
Cabinet air temp.
Thermostat cut out
Fan
Compressor
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