Toshiba MMU-AP0072H2UL-1 Service Manual page 95

Check code
Main Outdoor 7-segment display
remote
Check
Sub-code
control
code
01: Compressor 1 side
02: Compressor 2 side
P04 P04
00:
P05 P05
01: Compressor 1 side
02: Compressor 2 side
01: Compressor 1 side
02: Compressor 2 side
P07 P07
Detected indoor address
P10 P10
P12 — —
P13 P13 —
Location
of
Description System status
detection
IPDU Activation of All stop
high-pressure
SW
I/F Detection of All stop
open phase/
phase
sequence
Inverter DC
voltage (Vdc)
trouble
(compressor)
MG-CTT trouble
IPDU Heat sink All stop
I/F overheating
trouble
Indoor Indoor overflow All stop
unit trouble
Indoor Indoor DC fan Stop of
unit trouble corresponding
unit
I/F Outdoor liquid All stop
backflow
detection
trouble
Trouble detection
condition(s)
High-pressure SW is activated.
• Open phase is detected when
power is turned on.
• Inverter DC voltage is too high
(overvoltage) or too low
(undervoltage).
Temperature sensor built into IPM
(TH) is overheated.
• Float switch operates.
• Float switch circuit is open-
circuited or disconnected at
connector
• Motor speed measurements
continuously deviate from target
value.
• Over current protection is
activated.
<During cooling operation>
When system is in cooling
operation, high pressure is
detected in follower unit that has
been turned off.
<During heating operation>
When system is in heating
operation, outdoor PMV 1 or 3
continuously registers opening of
300p or less while under superheat
control.
95
Check items (locations)
• Check connection of highpressure
SW connector.
• Check for defect in Pd pressure
sensor.
• Check outdoor service valves
(gas side, liquid side) to confirm
full opening.
• Check for defect in outdoor fan.
• Check for defect in outdoor fan
motor.
• Check outdoor PMVs (PMV1, 4)
for clogging.
• Check indoor/outdoor heat
exchangers for clogging.
• Check for short-circuiting of
outdoor suction/discharge air
flows.
• Check SV2 circuit for clogging.
• Check for defect in outdoor P.C.
board (I/F).
• Check for trouble in indoor fan
system (possible cause of air
flow reduction).
• Check opening status of indoor
PMV.
• Check indoor-outdoor
communication line for wiring
trouble.
• Check for faulty operation of
check valve in discharge pipe
convergent section.
• Check gas balancing SV4 valve
circuit.
• Check SV5 valve circuit.
• Check for refrigerant
overcharging.
• Check for defect in outdoor P.C.
board (I/F).
• Check wiring of outdoor power
supply.
• Check power supply voltage.
• Check outdoor fan system
trouble.
• Check heat sink cooling duct for
clogging.
• Check IPM and heat sink for
thermal performance for faulty
installation.
(e.g. mounting screws and
thermal conductivity)
• Check for defect in A3-IPDU.
(faulty IPM built-in temperature
sensor (TH))
• Check float switch connector.
• Check operation of drain pump.
• Check drain pump circuit.
• Check drain pipe for clogging.
• Check for defect in indoor P.C.
board.
• Check connection of fan
connector and wiring.
• Check for defect in fan motor.
• Check for defect in indoor P.C.
board.
• Check impact of outside air
treatment (OA).
• Check full-close operation of
outdoor PMV (1, 3, 4).
• Check for defect in Pd or Ps
sensor.
• Check gas balancing circuit (SV2)
for clogging.
• Check balance pipe.
• Check SV3B circuit for clogging.
• Check defect in outdoor P.C.
board (I/F).
• Check capillary of oil separator oil
return circuit for clogging.
• Check for leakage of check valve
in discharge pipe convergent
section.
MG-CTT: Magnet contactor