E9 to E28 NKR Service Manual.pdf - Industrial Air

14.3.4 Low Temperature Compressor Oil Return Control
In heating operation, if the outdoor temperature falls below -10°C (E7 ~ 18NK), -8°C (E21 ~ 28NK) when
compressor starts, the compressor frequency will be regulated up to 600 seconds.
14.3.5 Cold Draught Prevention Control
When indoor pipe temperature is low, cold draught operation starts where indoor fan speed will be reduced.
14.3.6 Deice Operation
When outdoor pipe temperature and outdoor air temperature is low, deice operation start where indoor fan motor
and outdoor fan motor stop and operation LED blinks.
14.3.7 Demand Control
When the air-conditioner connected to Demand Response Enabling Devices (DRED), the power consumption
especially during peak hours could be controlled.
Three Demand response modes (DRM) are available
o DRM1 = Compressor cut off
o DRM2 = Operate at 50% of rated input power
o DRM3 = Operate at 75% of rated input power
During DRM, the Power Indicator blinks (3 seconds ON and 0.5 seconds OFF) to indicate the compressor cut off
status.
14.3.8 Pump down Operation by CN-S
A convenience method to activate pump down operation.
Control start condition:
o During power standby condition, short CN-S continuously between 1 second and 10 seconds.
Control stop condition:
o 480 seconds after pump down operation starts.
o CN-S is shorted again during pump down operation.
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