Mitsubishi Heavy Industries SRRM40HENG-L, Handbook, Page: 356 / 1106

354
FDT(N)-H
( )
YES YES
NO
NO
Are the heat
exchanger thermistor
characteristics OK, is
there no short
circuit?
YES
NO
Is the indoor
unit heat exchanger
thermistor connector
connection OK?
YES
NO
Is the air filter
clogged?
Correction
Washing
Adjustment
Is the heating
under overload?
Defective indoor unit PCB
Replacement (Defective indoor unit heat
exchanger thermistor input circuit)
Defective heat exchanger
thermistor Replacement
(1)
Heating overload
Note (1) To see whether or not it is over-
loaded, check the following:
u
Is the inside/outside air tem-
perature too high?
u
Is there any short circuit?
u
Is the refrigerant excessive?
5
Indoor unit
Check Lamp (yellow) 6 time flashes
Abnormality casued by insufficient refrigerant.
4
Indoor unit
Check Lamp (yellow) 5 time flashes
NO
YES
Is the
amount of refrigerant
circulation good? (If refrige-
rant is insufficient, the ca-
pillary tubes may be
plugged.)
Printed circuit board for indoor
unit no good replace.
Charge with refrigerant.
Replace capillary tubes.
NO
YES
Are the
characteristic values for
the heat exchanger
thermistor OK?
Replace heat exchanger thermistor.
Note (1) Refer to previous page for heat exchanger thermistor tempera-
ture resistance characteristic values.
YES YES
YES
NO
NO
Does the
voltage oscillate
between DC6 and 10V
between control switch
circuit board connector
(CnB) Y (White)
to Z (Black)?
Does the
voltage oscillate
between DC6 and
10V between indoor unit
PCB connector (CNB)
2 (White) to 3
(Black)?
YES
NO
NO
Is there
DC 10.8V
between control
switch circuit board con-
nector (CnB) X
(Red) to Z
(Black)?
Is there
DC 10.8V
between indoor unit
PCB connector (CNB)
1 (Red) to 3
(Black)?
YES
Defective indoor
unit PCB
Power
supply
reset
Is it
normalized?
NO
Unit is normal
(Intrusion of accidental
noise on the control switch
cord)
Defective control
switch PCB
(1)
The control switch wiring
(white) or (black) is broken or
have a defective connection.
Defective control switch
PCB Replacement
Defective indoor unit PCB
Replacement
The control switch wiring (red)
or (black) is broken or have a
defective connection.
1
Error display :
e 1
[Communication error between control switch ~ Indoor unit PCB]
Note (1) If it is normalized by changing PCB, judge the control switch or indoor
unit PCB (Communication error between control switch and unit) is
detective.
• Normal voltage for control switch wiring (DC)
Between X and Z : 10.5 ~ 10.8 V
Between Y and Z : 5 ~ 10.8 V
(ii) Only case of wired remote control model