Power Panel - LG RCWW-1 Operation & Maintenance Manual

n Power Panel
Compressor Magnetic Contactors Main Terminal Block
No Fuse Breaker OCR Neutral Terminal Block
Transformer
Voltage Monitoring Relay
Fuse
Fig. 13
Rated electrical input power input and related electric control components are installed in power panel. Power
input is structured in Terminal Block shape, Rated electrical input power which is approved to terminal block is
approved to Magnet switch for compressor control. 3 Phase Rated electrical input power input and Neutral
Terminal Block can make normal control power only if it is provided with N phase.
Magnet switch for compressor control consists of total 3, it conducts normal control through △ operation and Y-
△ operation of compressor. Magnet switch control is done through PLC output of control panel, operation con-
tact part condition of magnet switch is inputted to PLC again and it watches operation condition of magnet
switch during PLC control.
OCR(Over Current Relay) which is installed with magnet switch detects over current and send signal to PLC to
protect compressor from over current.
Rated electrical input power input normality is watched always by Voltage Monitoring Relay, and when abnormality is
detected, it sends signal to PLC and let it conduct alarm operation when abnormal power is provided. Power abnor-
mality that Voltage Monitoring Relay can detect includes over voltage, low voltage, open, short and imbalance
between phases.
Different from inputted R phase of 3 phase power, N phase 220V AC power which is neutral is used as power,
control power is provided through No Fuse Breaker.
Also, 24V AC which is power provided to PLC is made through Transformer inside power panel.
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