Installation manual
[ IX Troubleshooting ]
- 307 -
HWE10050 GB
(5) In the case of SV5b (Bypass valve)
This solenoid valve closes when energized (when the relay is on).
This valve turns off for five minutes after the completion of the defrost cycle, or when SV9 is on turned ON and the value of
63HS1 is greater than 3.5 MPa [507psi] during Heating-only or Heating-main operation at the minimum frequency. The valve
position can be determined by measuring and monitoring the changes in the pipe temperature on the downstream of SV5b
while the unit is de-energized. When the valve is open, high-temperature gas refrigerant passes through the pipe. Do not at-
tempt to check the pipe temperature by touching the pipe.
(6) In the case of SV5c (Bypass valve)
This solenoid valve opens when energized (when the relay is on).
Depending on the conditions during Cooling-only, Cooling-main, or Defrost (P450 and EP350 models only) operation, the so-
lenoid valves turn on. Check for proper operation on the LED and by listening for the operation sound of the solenoid valves.
(7) In the case of SV9 (Bypass valve)
This solenoid valve opens when energized (when the relay is on)
This valve turns on when the value of 63HS1 is greater than 3.5 MPa [507psi] during Heating-only or Heating-main operation
at the minimum frequency. The valve position can be determined by measuring and monitoring the changes in the pipe tem-
perature on the downstream of SV9 while the unit is energized. When the valve is open, high-temperature gas refrigerant
passes through the pipe. Do not attempt to check the pipe temperature by touching the pipe.
Outdoor Unit Fan
-4- Outdoor Unit Fan
(1) Fan motor
To check the revolution of the fan, check the inverter output state on the self-diagnosis LED, as the inverter on the outdoor
fan controls the revolutions of the fan.The revolution of the fan is approximately 680rpm(P200 - P300, EP200 mod-
els),790rpm(P350, P400, EP250, EP300 models), 750rpm (P450, EP350 models) at full speed.
When starting the fan, the fan runs at full speed for 5 seconds.
When setting the DIP SW1 as shown in the figure below, the inverter output [%] will appear. 100% indicates the full speed
and 0% indicates the stopping.
As the revolution of the fan changes under control, at the interphase or when the indoor unit operation capacity is low, the
revolution of the fan may change.
If the fan does not move or it vibrates, fan inverter board problem or fan motor problem is suspected. Refer to IX [4] -7- (2) [5]
"Check the fan motor ground fault or the winding."(page 326) and IX [4] -7- (2) [6] "Check the FAN board failure."(page 326)
(2) Electromagnetic contactor (52F)(P450, EP350 only)
If the outdoor unit fan is not operating correctly according to what is specified in the table below, check 52F for short-circuit.
Use the flowchart to identify possible problems.
Check that the right and left connectors for the fan motor are connected to the appropriate connectors in the electromagnetic
contactor.
Operation mode No. of outdoor unit fans
4-way valve Heat exchanger solenoid valve
52F
21S4a 21S4b SV4a SV4b SV4c SV4d
Cooling-only/
Cooling-main
1 (Left:Controller side) OFF OFF OFF OFF ON ON OFF
1 (Left:Controller side) OFF OFF OFF OFF ON OFF OFF
1 (Left:Controller side) OFF OFF OFF ON ON OFF OFF
2 OFF OFF ON ON ON OFF ON
2OFFOFFONONOFFOFFON
Heating-only/
Heating-main
2 ONONONONOFFONON
2 ONONONONOFFOFFON
Defrost 0 OFF OFF ON ON OFF OFF OFF
*ON/OFF status shown in the table above indicates the relay output of the valve coil.
12345678 9 10
ON
SW1