121
Compressor Drive Input/Output (VFD-02)
1. Power the unit OFF. Verify there is no damage to the wiring. Make sure all connections are secure and
connected. Verify wiring connections to the schematic. Refer to
for details.
2. Verify the unit is OFF. Check for open or short circuits in the wiring harness.
3. Power the unit ON. Check for voltage at the following terminals:
• Terminal L1 to ground. Verify reading to nameplate voltage.
• Terminal L2 to ground. Verify reading to nameplate voltage.
• Terminal L3 to ground. Verify reading to nameplate voltage.
• Terminal T1/U to ground. Voltage will vary with compressor speed.
• Terminal T2/V to ground. Voltage will vary with compressor speed.
• Terminal T3/W to ground. Voltage will vary with compressor speed.
Figure 54 - Compressor Drive
Humidity Temperature Sensor
Intake (HUM-1)/Space (HUM-2)/Discharge (HUM-3)
Refer to Figure 55 for component locations. Check the following:
1. Verify the wiring is connected properly to the terminal block.
2. Verify the DIP switches are set properly. Make sure switch 7 and 8 are ON.
3. Check the wiring is connected properly at the switch.
4. Make sure all the connections are clean, and that there is no condensation on the RH sensor circuit
board.
Figure 55 - Humidity/Temperature Sensors
T3 (98)
Compressor
3 Phase Input
3 Phase Input
Compressor
Compressor
3 Phase Input
T1 (96)
T2 (97)
L1 (91)
L3 (93)
L2 (92)
95
INPUT Ground
99
Compressor Ground
95
91
L1
92
L2
93
L3
HUM-1
HUM-3
1
3
4
2
7
6
5
8
O N
Sensor
Plug
BK
WH
RD
AI-3
AI-2
J14
1
8
24VDC
0-10V IN
COMMON
HUM-1
VIN
VOUT
CO
M
RD
BK
WH
INTAKE
HUM-2
COMMON
0-10V IN
24VDC
VIN
VOUT
CO
M
SPACE
7
8
9
J31
HUM-3
COM
VOUT
VIN
BK
RD
SHD
DISCH
