Friedrich VRP12K, Service And Parts Manual

Page: 139 / 221

139 PB
COMPONENTS TESTING
Fmc Board Pin Out
ID Coil – Heat Cond. Ret Air
IC Coil Inlet Supply Air
Comp Disch. Comp. Suct. Heat Liq.
Cool Liq. OD Coil OD Amb.
12V
GND
12V
GND
RS485 - Y
RS485 - Z
RS485 - A
RS485 - B
12V
GND
RS232 - TX
RS232 - RX
1. Check for 12 v to ground 3 places.
2. Check for 3.3 volts across thermistor pins.
3. Check resistance of thermistors (10 places). Refer to thermistor values (Figure 630).
Figure 618 (FMC Board)