Fan
Motor
060 - Blk
048 - Red
042 - Blk
036 - Blk
030 - Blk
Compr
Motor
CC - Compressor Contactor
HTR - Crankcase Heater (Optional)
CAP - Motor Capacitor
Condensate
Sensor
Common
Fan
L1
Compressor
Reversing Valve
Solenoid
0
W
2
G W
1
Y
1
F E L U A P V R C
Mark IV
PC
Board
Hi Pressure
Lo Pressure
Lo Temp
Ground
L1
L2
CC
Heater
IM 778 / Page 9
Typical Wiring Diagrams
Notes:
1. Unit is factory wired for 208V operation. If 230V
power supply is used, transformer must be
rewired by disconnecting the power lead from the
red transformer primary wire and connecting the
power lead to the orange transformer primary
wire. Place an insulation cap on the red trans-
former primary wire.
2. All temperature and pressure switches are nor-
mally closed.
3. Component layout shown below is typical. Some
components may not be used on this model or
voltage.
4. Mark IV/AC controller board contains a static sen-
sitive microprocessor. Proper grounding of field
service personnel should be observed or damage
to controller may result.
5. Terminal block on Mark IV/AC board provides 24
VAC at terminals R and C. All other outputs are 24
VDC.
6. Field supplied relays installed on the input ter-
minals (W1, W2, Y1 or G) may interfere with
proper unit operation. Never install relay coils
in series with inputs.
7. For more information pertaining to the Mark IV/AC
controller, refer to OM120.
Figure 10. Typical Mark IV/AC wiring diagram
COMPONENT LAYOUT
➀
COMPRESSOR CONTACTOR
➁
FAN CONTACTOR
➂
TRANSFORMER
➃
PC BOARD
➄
AUXILIARY RELAY
➅
CIRCUIT BREAKER
