Toshiba MMU-P0121H Service Manual page 48

Check Detected Check code
code position name
17 Inverter Current
detection
circuit system
alarm
18 Interface TE1 sensor
alarm
1C Interface Extension IC,
EEPROM
alarm
1d Outdoor Compressor
alarm
1F Outdoor Compressor
break down
21 Outdoor Inverter high-
pressure SW
system alarm
Cause Trouble detection
(Position) condition
Inverter current Status that current flows
detection over the set value thus
circuit inverter compressor
stopped is detected.
Outdoor heat Sensor resistance value
exchanger was infinity or zero
sensor (TE1) (Open, Short) (automatic
backup operation after
judgment)
Outdoor Outdoor P.C. board
interface P.C. (Interface) is not
board circuit operating correctly
Inverter Over-current was
compressor detected several
system circuit seconds after inverter
compressor was
activated.
Inverter current After inverter frequency
detection reduced by current
circuit release, over-current
was detected and
stopped.
Inverter high- High-pressure SW or IOL
pressure SW operated.
system circuit
n High-pressure
Pd ≥ 2.5MPa :
[21] is displayed.
n High-pressure
Pd < 2.5MPa :
[E5] is displayed.
3-45
Check item (Position)
• Check wiring of current detection circuit
system.
• Check outdoor P.C. board (IPDU) error.
• Check connection of TE1 sensor connector.
• Check characteristics of TE1 sensor
resistance value.
• Check outdoor P.C. board (Interface) error.
• Check power supply voltage.
• Check power supply noise.
• Check outdoor P.C. board (Interface) error.
• Check inverter compressor lock.
• Check power supply voltage (AC342–457V).
• Check wiring of inverter compressor system
and miss-phase.
• Check connection of connector on IPDU P.C.
board.
• Conductive check for crank case heater.
(Activation error check by liquid stagnation in
compressor)
• Check outdoor P.C. board (IPDU) error.
• Check power supply voltage (AC342–457V
for 50Hz, AC342–418V for 60Hz).
• Check cause of abnormal overload operation.
• Check current sensor detection circuit system.
• Check outdoor P.C. board (IPDU) error.
• Check outdoor fan system error.
• Check for blockage inside of cooling duct of
heat sink.
• Check inverter high-pressure SW error.
• Check IOL operation and case temp.
(Check cause of overload operation.)
• Check service valve is fully open.
• Check connection of outdoor fan connector.
• Check outdoor fan motor, running capacitor
error.
• Check for blockage in outdoor PMV.
1) Refrigerant choke circuit (PMV A)
2) Cooling bypass circuit (PMV B)
3) Liquid line check valve
(Cooling only model)
• Check for blockage in outdoor/indoor heat
exchanger.
• Short-circuit status between outdoor
discharge air and suction air
• Check Pd pressure sensor error.
• Check for blockage in hot gas bypass SV2
circuit.
• Check outdoor P.C. board (Interface) error.
• Check open valve status of indoor PMV.
• Check miswiring of communication line
between indoor and outdoor.