Mitsubishi Electric PUZ-HWM140VHA Service Manual page 46

Indication
Outdoor controller board
LED1 (Green) LED2 (Red)
3 blinking 1 blinking
Abnormality of discharging
temperature (TH4) and Comp.
surface temperature (TH33)
Abnormality of superheat due to
low discharge temperature
2 blinking Abnormal high pressure (High
pressure switch 63H operated.)
3 blinking Abnormality of outdoor fan motor
rotational speed
Protection from overheat
operation (TH3)
4 blinking Compressor overcurrent
breaking(Startup locked)
Compressor overcurrent breaking
Abnormality of current sensor (P.B.)
Abnormality of power module
5 blinking Open/short of outdoor
thermistors (TH4, TH33)
Open/short of outdoor thermistors
(TH3, TH32, TH6, TH7 and TH8)
6 blinking Abnormality of heat sink
temperature
7 blinking Abnormality of voltage
4 blinking 1 blinking Abnormality of room temperature
thermistor (TH1)
Abnormality of pipe temperature
thermistor /Liquid (TH2)
Abnormality of tank temperature
thermistor
4 blinking Abnormality of pipe
temperature
* Check code displayed on remote controller
** Refer to service manual for indoor unit.
OCH748
Check
Contents
code*
1 Check if stop valves are open.
U2
2 Check if connectors (TH4, LEV-A, and LEV-B) on outdoor con-
3 Check if unit is filled with specified amount of refrigerant.
U7
4 Measure resistance values among terminals on indoor valve and
1 Check if indoor/outdoor units have a short cycle on their air ducts.
2 Check if connector (63H) (63L) on outdoor controller board is not
U1
3 Check if heat exchanger and filter is not dirty.
4 Measure resistance values among terminals on linear expansion
1 Check the outdoor fan motor.
U8
2 Check if connector (TH3) (63HS) on outdoor controller board is
Ud
1 Check if connecting wire of indoor unit or remote controller is
UF
UP 2 Check if noise entered into transmission wire of remote controller.
3 Re-check error by turning off power, and on again.
UH
U6
1 Check if connectors (TH3, TH32, TH4, TH33 and TH7/6) on
U3
U4
2 Measure resistance value of outdoor thermistors.
1 Check if indoor/outdoor units have a short cycle on their air ducts.
U5
2 Measure resistance value of outdoor thermistor (TH8).
1 Check looseness, disconnection, and converse connection of
U9
2 Measure resistance value among terminals on compressor using
3 Check if power supply voltage decreases.
1 Check if connectors on indoor controller board are not discon-
P1
2 Measure resistance value of indoor thermistors.
P2
P9
1 Check if indoor thermistors(TH2 and TH5) are not disconnected
2 Check if stop valve is open.
P8
3 Check converse connection of extension pipe. (on plural units
4 Check if indoor/outdoor connecting wire is connected correctly.
Error
Inspection method
troller board are not disconnected.
outdoor linear expansion valve using a multimeter.
disconnected.
valve using a multimeter.
disconnected.
connected correctly.
outdoor controller board and connector (CN6) on outdoor power
board are not disconnected.
compressor wiring.
a multimeter.
nected.
from holder.
connection)
(on plural units connection)
46
Detailed
reference
page
P.22
P.23
P.22
P.23
P.25
P.25
P.25
P.25
P.23
P.22
P.23
P.23
P.24
**
**
**
P.27