8-3-1. Checking the outdoor unit
8-3. Checking the Outdoor System
8-3-2. Checking the defrost operation
Work procedure
Apply 220 V AC between terminals L1 and L2 on the
outdoor unit terminal plate.
•
Short-circuit the T-RUN terminal to the COM terminal
of TEST/T-RUN terminals.
•
The LED (red) on the control board must illuminate.
•
The compressor, fan motor, 4-way valve, and solenoid
valve (for the hot gas bypass) must turn ON.
(They turn ON about (70) seconds later after the power
is turned ON.)
•
No.
1
2
Check items (unit operation)
Work procedure
Connect a dummy resistor of 39 k ohm to the outdoor
coil temperature sensor connector.
•
Non-stop defrost
The maximum length of defrost operation is 12
minutes.
Defrost can also be released based on the below
conditions for the outdoor heat exchanger sensor.
*1 However, the condition is (68
°
F) or higher when
the outdoor air temperature is below 32
°
F.
Less than 2 minutes Not released
2 minutes or more 57.2
°
F or higher (*1)
•
No.
1
Check items (unit operation)
Indoor fan
Outdoor fan
CM
Solenoid valve
(for hot gas
bypass)
30 sec.
10 sec.
5 sec.
(80 Hz)
ON
ON
OFF
OFF
OFF
ON
Defrost start
Release
ON
Setting
Setting
LL Stop
NOTE
If the above check items are okay, but the outdoor unit does not operate, there may be a faulty
connection between the indoor unit and the outdoor unit.
Using forced defrost operation to check this function.
55
