Toshiba MMU-UP0051MH-E(TR) Service Manual page 108

Check code
Main Outdoor 7-segment display
remote
Check
Sub-code
controller
code
F16 F16 —
F23 F23 —
F24 F24 —
F29 — —
F31 F31 —
1∗: Compressor
1 side
2∗: Compressor
2 side
H01 H01
1∗: Compressor
1 side
2∗: Compressor
2 side
H02 H02
1∗: Compressor
1 side
2∗: Compressor
H03 H03
2 side
*1 Total shutdown in case of header unit
Continued operation in case of follower unit
Location
Description
of
detection
I/F Outdoor All stop
pressure
sensor wiring
trouble (Pd, Ps)
I/F Ps sensor All stop
trouble
I/F Pd sensor All stop
trouble
Indoor unit Other indoor Stop of
trouble corresponding
unit
I/F Outdoor All stop *1
EEPROM
trouble
Compressor Compressor All stop
P.C. board breakdown
Compressor Compressor All stop
P.C. board trouble (lockup)
MG-CTT trouble
Compressor Current All stop
P.C. board detection
circuit trouble
– 108 –
Check code detection
System status
condition(s)
Readings of high-pressure
Pd sensor and low-pressure
Ps sensor are switched.
Output voltages of both
sensors are zero.
Output voltage of Ps
sensor is zero.
Output voltage of Pd sensor
is zero (sensor open-
circuited).
Pd > 4.15MPa despite
compressor having been
turned off.
Indoor P.C. board does not
operate normally.
Outdoor P.C. board (I/F)
does not operate normally.
Inverter current detection
circuit detects overcurrent
and shuts system down.
Overcurrent is detected
several seconds after
startup of inverter
compressor.
Current flow of at least
specified magnitude is
detected despite inverter
compressor having been
shut turned off.
Check items (locations)
• Check connection of high-
pressure Pd sensor
connector.
• Check connection of low-
pressure Ps sensor
connector.
• Check for failure in
pressure sensors Pd and
Ps.
• Check for trouble in
outdoor P.C. board (I/F).
• Check for compressor
poor compression.
• Check for connection
trouble involving Ps sensor
and Pd sensor connectors.
• Check connection of Ps
sensor connector.
• Check for failure in Ps
sensor.
• Check for compressor
poor compression.
• Check for failure in 4-way
valve.
• Check for failure in outdoor
P.C. board (I/F).
• Check for failure in SV4
circuit.
• Check connection of Pd
sensor connector.
• Check for failure in Pd
sensor.
• Check for failure in outdoor
P.C. board (I/F).
• Check for failure in indoor
P.C. board (failure
EEPROM)
• Check power supply
voltage.
• Check power supply noise.
• Check for failure in outdoor
P.C. board (I/F).
• Check power supply
voltage.
(AC380V-415V ± 10%).
• Check for failure in
compressor.
• Check for possible cause
of abnormal overloading.
• Check for failure in outdoor
P.C. board (Compressor).
• Check for failure in
compressor.
• Check power supply
voltage.
(AC380V-415V ± 10%).
• Check compressor system
wiring, particularly for open
phase.
• Check connection of
connectors/terminals on
compressor P.C. board.
• Check conductivity of case
heater.
(Check for refrigerant
problem inside
compressor.)
• Check for failure in outdoor
P.C. board (Compressor).
• Check outdoor MG-CTT.
• Check current detection
circuit wiring.
• Check failure in outdoor
P.C. board (Compressor).