Check
SiBE12-908
170
Service Diagnosis
3.12
Rotating Pulse Input on Outdoor Unit PCB Check
Check No.23
< For propeller fan motor or humidification fan>
Make sure voltage of 270 ± 30 V is applied.
1. Set power ON and operation OFF. Remove connector S70 or S72.
2. Check that the voltage between No. 4 pin and No.7 pin is 270 VDC.
3. Check that the control voltage between No. 3 pin and No. 4 pin is 15 VDC.
4. Check that the RPM command voltage between No. 2 pin and No. 4 pin is 5 VDC.
5. Set power OFF and operation OFF. Connect connector S70 or S72.
6. Check whether two pulses (0 - 15 V) are input at No. 1 pin and No. 4 pin when the fan motor
is rotated 1 turn by hand.
Fuses are commonly used as follows. Refer to the corresponding circuit diagram.
When FU2 is melted, check outdoor fan for proper function.
If NG in step 2
→
Defective PCB
→
Replace the PCB.
If NG in step 4
→
Defective Hall IC
→
Replace the DC fan motor.
If OK in both steps 2 and 4
→
Replace the PCB.
Propeller fan motor: S70, Humidification fan motor: S72
<For Hygroscopic fan>
Check that the connectors HK1, HK2, HK3 for proper connection.
1. Check that the supply voltage between HK1 and HK3 is 5VDC.
*Check when the machine is not in suspend mode.
2. If NG in step 1
→
Defective PCB
→
Replace the PCB.
Therefore, when the FU2 is melted, check rotor motor for proper function.
FU1
SW power supply
Four way valve
Hygroscopic fan
FU2
Outdoor fan
Humidification fan
FU1
SW power supply
Four way valve
Hygroscopic fan
FU2
Outdoor fan
Humidification fan
1
2
3
4
5
6
7
RPM command pulse input (0-15V)
15V
DC270V
(R3477)
S70 or S72
PCB
