Toshiba MMU-AP0074YH-E Service Manual page 85

Check code
Outdoor 7-segment display
Main
remote
F24 –
controller
F24 F24 –
F29 – –
F31 F31 –
01: Compressor 1
side
02: Compressor 2
side
H01 H01
03: Compressor 3
side
01: Compressor 1
side
02: Compressor 2
side
03: Compressor 3
side
H02 H02
01: Compressor 1
side
02: Compressor 2
H03 H03
side
03: Compressor 3
side
H05 H05 –
H06 H06 –
*1 Total shutdown in case of header unit
Continued operation in case of follower unit
Location
AI-NET central
of Description
control
detection
remote
controller
I/F Pd sensor
error
43
Indoor Other indoor
12 unit error
I/F Outdoor
EEPROM
1C
error
IPDU Compressor
breakdown
1F
IPDU Compressor
error (lockup)
MG-CTT error
1d
IPDU Current
detection
circuit error
17
I/F TD1 sensor
miswiring
(incomplete
insertion)
I/F Activation of
low-pressure
protection
20
System Error detection
status condition(s)
All stop Output voltage of Pd
sensor is zero (sensor
open-circuited).
Pd > 4.15 MPa despite
compressor having been
turned off.
Stop of Indoor P.C. board does not
corresponding operate normally.
unit
All stop *1 Outdoor P.C. board (I/F)
does not operate normally.
All stop Inverter current detection
circuit detects overcurrent
and shuts system down.
All stop Overcurrent is detected
several seconds after
startup of inverter
compressor.
All stop Current flow of at least
specified magnitude is
detected despite inverter
compressor having been
shut turned off.
All stop Discharge temperature of
compressor 1 (TD1) does
not increase despite
compressor being in
operation.
All stop Low-pressure Ps sensor
detects operating pressure
lower than 0.02 MPa.
84
Check items (locations)
• Check connection of Pd
sensor connector.
• Check for defect in Pd sensor.
• Check for defect in outdoor
P.C. board (I/F).
• Check for defect in indoor P.C.
board (faulty EEPROM)
• Check power supply voltage.
• Check power supply noise.
• Check for defect in outdoor
P.C. board (I/F).
• Check power supply voltage.
(AC200 V ± 10 %).
• Check for defect in
compressor.
• Check for possible cause of
abnormal overloading.
• Check for defect in outdoor
P.C. board (A3-IPDU).
• Check for defect in
compressor.
• Check power supply voltage.
(AC200 V ± 10 %).
• Check compressor system
wiring, particularly for open
phase.
• Check connection of
connectors / terminals on A3-
IPDU P.C. board.
• Check conductivity of case
heater.
(Check for refrigerant
entrapment inside
compressor.)
• Check for defect in outdoor
P.C. board (A3-IPDU).
• Check outdoor MG-CTT.
• Check current detection circuit
wiring.
• Check defect in outdoor P.C.
board (A3-IPDU).
• Check installation of TD1
sensor.
• Check connection of TD1
sensor connector and wiring.
• Check resistance
characteristics of TD1 sensor.
• Check for defect in outdoor
P.C. board (I/F).
• Check service valves to
confirm full opening
(both gas and liquid sides).
• Check outdoor PMVs for
clogging (PMV1, 2).
• Check for defect in SV2 or SV4
circuits.
• Check for defect in low-
pressure Ps sensor.
• Check indoor filter for clogging.
• Check valve opening status of
indoor PMV.
• Check refrigerant piping for
clogging.
• Check operation of outdoor fan
(during heating).
• Check for insufficiency in
refrigerant quantity.
MG-CTT: Magnet contactor