Mitsubishi Electric CITY MULTI PQRY-P200YMF-C Service Handbook page 108

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 1.0 kg/cm
operation stops immediately.
1302 High pressure 1. When press. sensor detects
abnoramlity 1 28kg/cm
(Heat source during operations (the first
unit) time), heat source unit stops
once, mode is changed to re-
start mode after 3 minutes, then
the heat source unit restarts.
2. When 30kg/cm
more pressure is detected
again (the second time) within
30 minutes after stop of heat
source unit,error stop is ob-
served with code No. "1302" dis-
played.
3. When 28kg/cm
more pressure is detected 30
or more minutes after stop of
heat source unit, the detection
is regarded as the first time and
the process shown in 1 is ob-
served.
4. 30 minutes after stop of heat
source unit is intermittent fault
check period with LED dis-
played.
5. Error stop is observed immedi-
ately when press. switch
(30
operates in addition to pressure
sensor.
2 G (0.098MPa),
2 G (2.47MPa) or more
2
G (2.94MPa) or
2 G (2.47MPa) or
+0
+0
2
kg/cm G (2.94 MPa))
–1.5
–1.5
Cause
1) Internal pressure is dropping due
to a gas leak.
2) The low pressure pressure sensor
is defective.
3) Insulation is torn.
4) A pin is missing in the connector,
or there is faulty contact.
5) A wire is disconnected.
6) The control board's low pressure
pressure sensor input circuit is de-
fective.
1) Poor operations of indoor LEV.
2) Poor operations of BC controller
LEV:
Heating-only, heating-principal:
LEV3
3) Poor operations of BC controller
SVM:
Cooling-only, defrost
4) Poor operations of BC controller
SVA:
Cooling-only, cooling-main
5) Poor operations of BC controller
SVB:
Heating-only, heating-main
6) Solenoid valve SV (3 ~ 6, SV71,
72) trouble.
Cooling-only, cooling-main
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
on indoor unit fan.
12)Dust on indoor unit heat exchanger.
13)Indoor unit fan block, motor trouble.
8)~13) : Rise in high pressure
caused by lowered condensing
capacity in heating-only and
heating-principal operation.
14)Short cycle of heat source unit.
15)Dust on heat source unit heat ex-
changer.
16)Heat source unit fan block, motor trou-
ble, poor operations of fan controller.
14)~16):Rise in high press.
caused by lowered condensing
capacity in cooling-only and
cooling-pincipal operation.
17)Poor operations of solenoid valves
SV1, 2 (Bypass valves (SV1, 2) can
not control rise in high pressure).
18)Thermistor trouble (TH2, TH5, TH6).
19)Pressure sensor trouble.
20)Control circuit board thermistor
trouble, press. sensor input circuit
trouble.
–107–
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, SV71, 72
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 heat source unit and take mea-
sures to trouble.
Check heat source unit fan
See Trouble check of heat source
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.