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9-4-1. Outdoor control circuit board
Refer to 9-3-1. Checking the outdoor unit.
NOTE: Do not remove or insert the outdoor control circuit board connector when power is being supplied to it.
(The controller will be damaged.)
9-4-2. HIC
Perform the continuity tests shown in the table above. Locations which are not as shown in the table have suffered HIC
failures.
NOTE: Ordinarily, the red lead of the tester has negative polarity. However, the reverse may be true, particularly with digital
testers. Use caution.
9-4-3. Fuse
Check the continuity visually or with a tester.
9-4-4. Compressor
Check for an open circuit in the compressor coil winding.
9-4-5. Compressor protective sensor (compressor discharge temperature thermistor)
Check that the sensor is securely contained in the thermostat holder.
9-4-6. Outdoor fan motor
Turn the fan slowly by hand.
●
If the fan rotates easily:
a
Replace the running capacitor on the outdoor control circuit board.
b
Check for an open circuit in the fan motor coil winding.
c
Use the tester AC range to check whether voltage is reaching the connector on the outdoor fan motor circuit board. If
the needle moves, the result is normal.
●
If the fan does not rotate easily:
a
Check whether something is obstructing the fan, or if the fan itself is coming into contact with the outer case, preventing
it from rotating. Correct if necessary.
b
Otherwise, the fan motor bearings have seized. Replace the bearings.
9-4-7. 4-way valve
Of the outdoor control circuit board connector T-RUN/TEST terminals, short-circuit the T-RUN terminal to the COM terminal.
Perform a test run of the unit alone, and check whether the 4-way valve inside the outdoor unit produces a click sound.
9-4-8. Coil thermistor
Check that the sensor is securely contained in the thermostat holder.
HIC measurement points
Continuity
T
ester polarity
+
(Black)
–
(Red)
+
–
+
–
U
V
W
∞
∞
+
U
V
W
Below
1k
Ω
Below
1k
Ω
+
U
V
W
–
U
V
W
–
