Heat Controller VMC18SB-1/VMH18SB-1 Heat Pump User Manual


 
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Only for training and service purposes
Part 2 Functions & Controls
5.6 Power Relay Control
Power relay turns on 1 second later after the power is supplied to the outdoor unit.
Control sequence : power on PTC operating power relay on
5.7 Inverter
1. The single phase power AC is converted into DC.
2. The single phase power DC is converted into a three phase chopped DC voltage with a variable frequency.
3. When the frequency changes, the rotation speed of the compressor changes resulting in a changed refrigerant circu-
lation. This leads to changeable amount of the heat exchange per unit.
3Ø
Comp.
Motor
U
UVW
V
W
+