Toshiba MMU-AP0057MH-E Service Manual page 72

Check code
Main Outdoor 7-segment display
remote
Check
Sub-code
controller
code
01:
Compressor 1
side
02:
Compressor 2
side
H02 H02
01:
Compressor 1
side
H03 H03
02:
Compressor 2
side
H05 H05 —
H06 H06 —
H07 H07 —
*1 Total shutdown in case of header unit
Continued operation in case of follower unit
Location
Description
of
detection
IPDU Compressor
problem
(lockup)
MG-CTT
problem
IPDU Current
detection
circuit problem
I/F TD1 sensor
miswiring
(incomplete
insertion)
I/F Activation of
low-pressure
protection
I/F Low oil level
protection
Problem detection
System status
condition(s)
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 0.02MPa.
All stop Operating compressor
detects continuous state of
low oil level for about 2 hours.
– 72 –
Check items (locations)
• Check for defect in
compressor.
• Check power supply voltage.
(AC380-415V ± 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
problem 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, 3).
• 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.
<All outdoor units in
corresponding line to be
checked>
• Check balance pipe
service valve to confirm full
opening.
• Check connection and
installation of TK1, TK2,
TK4, and TK5 sensors.
• Check resistance
characteristics of TK1,
TK2, TK4, and TK5
sensors.
• Check for gas or oil leak in
same line.
• Check for refrigerant
problem inside
compressor casing.
• Check SV3A, SV3B,
SV3C, SV3D valves for
defect.
• Check oil return circuit of
oil separator for clogging.
• Check oil equalizing circuit
for clogging.
MG-CTT: Magnet contactor