12-1
TROUBLESHOOTING
SM DUO38I 1-A.2 GB
12. TROUBLESHOOTING
WARNING!!!
When Power Up – the whole outdoor unit controller, including the wiring, is under HIGH
VOLTAGE!!!
Never open the Outdoor unit before turning off the Power!!!
When turned off, the system is still charged (400V)!!!
It takes about 3 Min. to discharge the system.
Touching the controller before discharging may cause an electrical shock!!!
For safe handling of the controller please refer to section 1.6 below.
1.1 Dual Split System Failures and Corrective Actions
No
SYMPTOM
PROBABLE CAUSE
CORRECTIVE ACTION
1
Power supply indicator at
indoor unit (Red LED) does
not light up.
No power supply
Check power supply from the outdoor. If
power supply is OK, check display and
display wiring. If OK, replace controller.
Unit in heat mode
and coil is still not
warm.
Change to cool mode and check.
2
The outdoor unit is in
the opposite mode.
Change operation mode and check if fan
starts.
Indoor fan does not start
(louvers are opened and
Green LED does light up)
Problem with PCB or
capacitor
Change to high speed and Check power
supply to motor is higher than 130VAC
(for Triac controlled motor) or higher
than 220VAC for fixed speed motors, if
OK replace capacitor, if not OK replace
controller
3
Compressor does not start
Jumper settings of
outdoor unit is not
correct
Use diagnostics (see 1.2 below)
information on MSMP board.
4
One indoor is operating, in
cool mode, with no
capacity, and the other unit
has water leaks/freezing
problems
5
One indoor is operating in
heat mode with a limited
capacity, and the coil on
the other unit is very hot.
The communication
wires of the two
indoor units are
switched
Check and correct the communication
wires connection
6
Compressor operate but
unit generate no capacity
EEV is stuck in close
position
Check EEV
7
One unit only is operating
Communication
problems
Use diagnostics information on MSMP
board (see 1.2 below).
8
All others
Specific problems of
indoor or outdoor
units
Use diagnostics information on MSMP
board (see 1.2 below), and perform
action items as recommended in single
split systems
