Mitsubishi Electric PURY-80TMU Service Handbook page 89

Checking code Meaning, detecting method
1301 Low pressure When starting from the stop mode
abnoramlity for the first time, (if at the start of bind
power transmission, the end of bind
power transmission, and in the mode
when the thermostat goes OFF im-
mediately after the remote control
goes ON, the following compressor
start time is included), if the low pres-
sure pressure sensor before start-
ing is at 0.098MPa (14.2psi), opera-
tion stops immediately.
1302 High pressure 1. When press. sensor detects
abnoramlity 1 2.47MPa (398.2psi) or more dur-
(Outdoor unit) ing operations (the first time),
outdoor unit stops once, mode
is changed to restart mode af-
ter 3 minutes, then the outdoor
unit restarts.
2. When 2.94MPa (426psi) or
more pressure is detected
again (the second time) within
30 minutes after stop of outdoor
unit,error stop is observed with
code No. "1302" displayed.
3. When 2.47MPa (398psi) or
more pressure is detected 30
or more minutes after stop of
outdoor unit, the detection is re-
garded as the first time and the
process shown in 1 is observed.
4. 30 minutes after stop of outdoor
unit is intermittent fault check
period with LED displayed.
5. Error stop is observed immedi-
ately when press. switch
(2.94
rates in addition to pressure
sensor.
1) Internal pressure is dropping due
2) The low pressure pressure sensor
3) Insulation is torn.
4) A pin is missing in the connector,
5) A wire is disconnected.
6) The control board's low pressure
1) Poor operations of indoor LEV.
2) Poor operations of BC controller
3) Poor operations of BC controller
4) Poor operations of BC controller
5) Poor operations of BC controller
6) Solenoid valve SV (3 ~ 6) trouble.
7) Setting error of connection address.
8) Poor operations of ball valve.
9) Short cycle of indoor unit.
10)Clogging of indoor unit filter.
11) Fall in air volume caused by dust
12)Dust on indoor unit heat exchanger.
+0
+0
MPa (426 psi)) ope- 13)Indoor unit fan block, motor trouble.
-0.15 -21
14)Short cycle of outdoor unit.
15)Dust on outdoor unit heat exchanger.
16)Outdoor unit fan block, motor trou-ble,
17)Poor operations of solenoid valves
18)Thermistor trouble (TH5, TH6).
19)Pressure sensor trouble.
20)Control circuit board thermistor
Cause
to a gas leak.
is defective.
or there is faulty contact.
pressure sensor input circuit is de-
fective.
LEV:
Heating-only, heating-principal:
LEV3
Defrost: LEV3
SVM:
Cooling-only, defrost
SVA:
Cooling-only, cooling-main
SVB:
Heating-only, heating-main
Cooling-only, cooling-main
on indoor unit fan.
8)~13) : Rise in high pressure
caused by lowered condensing
capacity in heating-only and
heating-principal operation.
poor operations of fan controller.
14)~16):Rise in high press.
caused by lowered condensing
capacity in cooling-only and
cooling-pincipal operation.
SV1, 2 (Bypass valves (SV1, 2) can
not control rise in high pressure).
trouble, press. sensor input circuit
trouble.
–88–
Checking method & Countermeasure
Refer to the item on judging low pres-
sure pressure sensor failure.
Check operations status by actually
performing cooling or heating opera-
tions.
Cooling : Indoor LEV
LEV1, 3 (BC)
SVA (BC)
SV3~6
Heating : Indoor LEV
LEV3 (BC)
SVB (BC)
See Trouble check of LEV and sole-
noid valve.
Check address setting of indoor unit
connector.
Confirm that ball valve is fully open-ed.
Check indoor unit and take measures
to trouble.
Check outdoor unit and take measures
to trouble.
Check outdoor unit fan
See Trouble check of outdoor unit
fan.
See Trouble check of solenoid valve.
Check resistance of thermistor.
Check Trouble check of pressure
sensor.
Check inlet temperature and press. of
sensor with LED monitor.