Demand Control; Control Of Ih Energization Without The Compressor In Operation - Mitsubishi Electric HP120TNU-A Service Handbook

[5-2 Outdoor Unit Control ]
5-2-17

Demand Control

Cooling/heating operation can be prohibited (Thermo-OFF) by an external input to the indoor units.
When DIP SW6-8 is set to ON, the 4-step DEMAND control is enabled.
Eight-step demand control is possible in the system with two outdoor units.
For details, refer to the following page(s). [2-4-7 Various Control Methods Using the Signal Input/Output Connector on Outdoor
Unit]
5-2-18

Control of IH energization without the compressor in operation

IH is used to heat the compressor motor on the stopped outdoor unit to make liquid refrigerant in the compressor evaporate
or to keep liquid refrigerant from flooding the compressor.
Initial power on after power is turned on: Stays on for 12 hours, and then transitions to the operation that is performed while
the compressor is stopped
When the compressor is stopped: Stays on for 30 minutes after the compressor stopped, and then repeats the off-on cycle
at 30-minute intervals
Lit LED1 on the INV board indicates that the INV board is energized by an IH.
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