Mitsubishi Electric PUZ-SM100VKA2 Service Manual page 65

Indication
Outdoor controller
board
LED1 (Green) LED2 (Red)
2 blinking 5 blinking Serial communication error
<Communication between outdoor
controller board and outdoor power board>
<Communication between outdoor
controller board and M-NET P.C. board>
Communication error of M-NET system
3 blinking 1 blinking Abnormality of comp. surface
thermistor(TH33) and discharge
temperature (TH4)
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
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 discharge thermistor (TH4)
and comp. surface thermistor (TH32)
Open/short of outdoor thermistors
(TH3, TH6, TH7 and TH8)
6 blinking Abnormality of heatsink
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 pipe temperature
thermistor/Condenser-Evaporator
2 blinking Abnormality of drain sensor (DS)
Float switch(FS) connector open
Indoor drain overflow protection
3 blinking Freezing (cooling)
4 blinking Abnormality of pipe temperature
*1 Check code displayed on the remote controller
*2 Refer to the indoor unit's service manual.
OCH774A
Check
Contents
code
Ed
A0–A8
U2
U7
U1
U8
UF
UP
UH
U6
U3
U4
U5
U9
P1
P2
P9
P4
P5
P6
P8
65
Error
Inspection method
*1
1. Check if connector (CN4) on outdoor controller
board and outdoor power board is not
disconnected.
2. Check if there is poor connection of connector on
outdoor controller board(CNMNT and CNVMNT).
3. Check M-NET communication signal.
1. Check if stop valves are open.
2. Check if connectors (TH4, TH33, LEV-A, and LEV-B)
on outdoor controller board are not disconnected.
3. Check if unit is filled with specified amount of refrigerant.
4. Measure resistance values among terminals on indoor
valve and outdoor linear expansion valve using a
tester
1. Check if indoor/outdoor units have a short cycle on their air ducts.
2. Check if connector (63H) on outdoor controller
board is not disconnected.
3. Check if heat exchanger and filter is not dirty.
4. Measure resistance values among terminals on
linear expansion valve using a tester.
1. Check the outdoor fan motor.
2. Check if connector (TH3) on outdoor controller
board is disconnected.
1. Check if stop valves are open.
2. Check looseness, disconnection, and reversed
connection of compressor wiring.
3. Measure resistance values among terminals on
compressor using a tester.
4. Check if outdoor unit has a short cycle on its air duct.
1. Check if connectors(TH3,TH4,TH6 ,TH7 and TH33)on
outdoor controller board and connector (CN6) on outdoor
power board are disconnected.
2. Measure resistance value of outdoor thermistors.
1. Check if indoor/outdoor units have a short cycle
on their air ducts.
2. Measure resistance value of outdoor
thermistor(TH8).
1. Check looseness, disconnection, and reversed
connection of compressor wiring.
2. Measure resistance value among terminals on
compressor using a tester.
3. Check if power supply voltage decreases.
4. Check the wiring of CN52C.
1. Check if connectors (CN20, CN21, CN29 and
CN44) on indoor controller board are not
disconnected.
2. Measure resistance value of indoor thermistors.
1. Check if connector (CN31)(CN4F) on indoor
controller board is not disconnected.
2. Measure resistance value of indoor thermistors.
3. Measure resistance value among terminals on
drain pump using a tester.
4. Check if drain pump works.
5. Check drain function.
1. Check if indoor unit has a short cycle on its air duct.
2. Check if heat exchanger and filter is not dirty.
3. Measure resistance value on indoor and outdoor fan motors.
4. Check if the inside of refrigerant piping is not clogged.
1. Check if indoor thermistors(TH2 and TH5) are
not disconnected from holder.
2. Check if stop valve is open.
3. Check reversed connection of extension pipe.
(on plural units connection)
4. Check if indoor/outdoor connecting wire is
connected correctly. (on plural units connection)
Detailed
reference
page
P. 37
P. 38
–P. 41
P. 31
P. 32
P. 31
P. 32
P. 34
P. 35
P. 34
P. 32
P. 31
P. 32
P. 32
P. 33 to
P. 34
*2
*2
*2
*2
*2
*2
*2