Toshiba MMU-P0121H Service Manual page 51

Check Detected Check
code position code name
99 Remote Indoor
controller remote
controller
communica
tion alarm
9A Indoor Indoor
miswiring/
misconnecti
on
9F Indoor Indoor PMV
blockage
A0 Interface TD1 sensor
alarm
A1 Interface TD2 sensor
alarm
A2 Interface TS1 sensor
alarm
Cause Trouble detection
(Position) condition
Indoor remote Serial between indoor main
controller P.C. board (MCC-1361)
communicatio and remote controller
n circuit interruption.
Miswiring or By change of detection
misconnectio value of indoor unit temp.
n of indoor sensor or pressure sensor
unit after operation has started.
¤ Judgment time : Approx.
15 minutes after
activation
• Cooling : When changed
value of TC1 is 5°C or
less.
• Heating : When changed
value of pressure sensor
is 0.5MPa or less.
Judgment of Status that refrigerant did
refrigerant not flow in indoor unit was
circulation detected.
volume
• Compared with TA temp.,
shortage
TC1 and TC2 temp. are
continuously below 4°C
for 60 minutes.
Discharge Sensor resistance value is
temp. sensor infinity or zero (Open,
(TD1) Short).
Discharge Sensor resistance value is
temp. sensor infinity or zero (Open,
(TD2) Short).
Suction temp. Sensor resistance value is
sensor (TS1) infinity or zero (Open,
Short).
• Check inter-unit wire (ABC).
• Check disconnection and connector contact
error.
• Check remote controller error.
• Check failure of indoor main P.C. board
(MCC-1361).
• Check duplication of indoor unit No.1.
(When group operation is set up.)
• Check miswiring of indoor unit which alarm is
displayed.
• Check for blockage in pipe of indoor unit which
alarm is displayed.
• Check refrigerant shortage.
[NOTE]
When checking miswiring, follow the items
below. Otherwise, misjudgment may be caused.
1) Check miswiring after outdoor unit stops 20
minutes or more.
Microprocessor is locked so that miswiring
check function does not operate forcibly for 2
minutes and 30 seconds after power has been
turned on.
2) Check miswiring under the following
conditions.
In cooling
In heating
3) When group operation for other outdoor
system is performed, miswiring check
function cannot
be used.
• Check indoor PMV open valve opening status.
• Check characteristics of TC1, TC2, and TA
sensor resistant value.
• Check indoor pressure sensor error.
• Check indoor PMV connector and wiring.
• Check for breakage and blockage of pipe.
• Check operation status of outdoor
compressor.
(When outdoor fan operates and compressor
stops, error is judged at indoor side. In this
case, check outdoor side.)
• Check connection of TD1 sensor connector.
• Check characteristics of TD1 sensor
resistance value.
• Check outdoor P.C. board (Interface) error.
• Check connection of TD2 sensor connector.
• Check characteristics of TD2 sensor
resistance value.
• Check outdoor P.C. board (Interface) error.
• Check connection of TS1 sensor connector.
• Check characteristics of TS1 sensor
resistance value.
• Check outdoor P.C. board (Interface) error.
3-48
Check item (Position)
Room temp. : 18 to 32°C
Outside temp. : 15 to 43°C
Room temp. : 18 to 32°C
Outside temp. : -15 to 15°C