12-4
TROUBLESHOOTING
SM HDDHED 2-A.1 GB
Indoor indicators
Outdoor indicators
Failure
Possible Reasons/Corrective
actions
2* 7
segments
LEDs
(RUN,COOL,HEAT)
D40
D41
D42
D43
PL
HEAT OFF 3S and
blink 21 times
□
■
■
□
DC under voltage
AC power supply voltage is
1.
less than 150VAC
Outdoor PCB circuit
2.
malfunction
EU
■
■
■
Stop rise/HZ down due to
HST over heating protection
Insufficient grease on heatsink
1.
or poor connection of heatsink
to PCB
Outdoor PCB problem.
2.
U7
■
□
□
The RV is abnormal
Supply voltage is lower than
1.
AC175V
Wiring terminal of RV is loosen
2.
or broken
RV is damaged
3.
U9
■
■
□
Zero-crossing protection
(ODU)
Replace outdoor controller
FH
■
■
■
□
Stop rise/HZ down due to
IDU defrosting protection
Poor air-return in indoor unit
1.
Fan speed is abnormal
2.
Evaporator is dirty.
3.
12.1.4
Checking the refrigeration system
Checking system pressures and other thermodynamic measures should be done when system
is in Test Mode (in Test mode, system operates in fixed settings). The performance curves
given in this manual are given for unit performance in test mode when high indoor fan speed is
selected.
Entering test mode please refer to section 11- Control system.
12.2
Simple procedures for checking the Main Parts
12.2.1
Checking Mains Voltage.
Confirm that the Mains voltage is between 198 and 264 VAC. If Mains voltage is out of this range,
abnormal operation of the system is expected. If in range check the Power (Circuit) Breaker and
look for broken or loosed cable lugs or wiring mistake(s).
12.2.2
Checking Power Input.
If Indoor unit power LED is unlighted, power down the system and check the fuse of the Indoor
unit. If the fuse is OK replace the Indoor unit controller. If the fuse has blown, replace the fuse
and power up again.
Checking Power Input procedure for the Outdoor unit is the same as with the Indoor unit.
12.2.3
Checking the Outdoor Fan Motor.
Check the voltage between two pins Hi and N of connector OFAN on controller, normal voltage
is 220~240VAC.
12.2.4
Checking the Compressor.
The compressor is brushless permanence magnetic DC motor. Three coil resistance is same.
Check the resistance between three poles. The normal value should be ~ 0.45 Ohm ( at 20
O
C).
Pay attention U,V, W are respective to connect to RED,YELLOW,BLUE wires ~ 0.54 Ohm (at
25
O
C).
12.2.5
Checking the Reverse Valve (RV).
Running in heating mode, check the voltage between two pins of reverse valve connector, normal
voltage is 220~240VAC.
