Mitsubishi Electric PQRY-P200YEM-A Service Handbook page 116

Checking code Meaning, detecting method
2135 Freezing of 1. If the water heat exchanger
the water heat freeze prevention thermostat op-
exchanger. erates (OFF at 3±1°C) (the first
time) the heat source unit stops
temporarily enters the 3-minute
restart prevention mode, the re-
starts after 3 minutes.
2. If the water heat exchanger
freeze prevention thermostat op-
erates (OFF at 3±1°C) again (the
second time) within 30 minutes
after the heat source units stops
according to 1. above, an abnor-
mal stop is performed and at that
time, "2135" is displayed.
3. If the water heat exchanger freeze
prevention thermostat operates
(OFF at 3±1°C) again longer than
30 minutes after the heat source
unit stops according to 1. above,
it is treated as having been de-
tected the first time and operation
is the same as in 1. above.
2500 Leakage (water) When drain sensor detects flooding
abnormality during drain pump OFF.
2502 Drain pump When indirect heater of drain sensor
abnormality is turned on, rise in temperature is
20 deg. or less (in water) for 40 sec-
onds, compared with the temperature
detected before turning on the indi-
rect heater.
2503 Drain sensor Short/open is detected during drain
abnormality pump operations. (Not detected
when drain pump is not operating.)
Short
Open : –40°C or less detected
Operation of When float switch operates (point of
float switch contact : OFF), error stop is observed
with code No. "2503" displayed.
3152 Abnormal 1. If the temperature inside the con-
temperature trol box is detected to be 70°C or
inside the more during operation (the first
Inverter time it is detected), the heat source
control box unit is stopped temporarily, the
system enters the 3-minute restart
prevention mode, then restarts the
heat source unit after 3 minutes.
2. If the temperature inside the con-
trol box is detected to be 70°C or
more during operation (the second
time it is detected) again within 30
minutes after the heat source unit
stops according to 1. above, an
abnormal stop is performed and
at that time, "3152" is displayed.
3. If the temperature inside the control
box is detected to be 70°C or more
again during operation longer than
30 minutes after the heat source unit
stops according to 1. above, it is
treated as having been detected the
first time and operation is the same
as in 1 above.
1) Failure of the heat source water cir-
2) Heating equipment out of order
3) Clogged or dirty water heat ex-
4) Lead wire to the water heat ex-
5) Connector to the water heat ex-
6) Faulty water heat exchanger freeze
7) Faulty water heat exchanger freeze
1) Water leak due to humidifier or the
1) Drain sensor sinks in water because
2) Broken wire of indirect heater of drain
3) Detecting circuit (circuit board)
1) Thermistor trouble.
2) Poor contact of connector.
: 90°C or more detected 3) Full-broken of half-broken thermistor
4) Indoor unit circuit board (detecting
1) Drain up input trouble.
2) Poor contact of float switch circuit.
3) Float switch trouble.
1) Cooling air passage closed.
2) Rise in the ambient temperature.
3) Faulty power transistor.
4) Faulty thermistor
5) Faulty thermistor input circuit on the
6) Faulty cooling fan, connector pulled
7) Faulty LEV 1 for inverter cooling, con-
8) Faulty cooling fan output circuit on the
9) Faulty cooling fan output circuit on the
10) Faulty LEV 1 output circuit for inverter
Cause
culating pump to operate.
changer
changer freeze prevention thermo-
stat is disconnected.
changer freeze prevention thermo-
stat is pulled out.
prevention thermostat input circuit on
the relay board.
prevention thermostat input circuit on
the control board.
like in trouble.
drain water level rises due to drain wa-
ter lifting-up mechanism trouble.
sensor.
trouble.
(insufficient insertion)
wire.
circuit) trouble.
control board.
out.
nector pulled out.
relay board.
control board.
cooling on the control board.
–115–
Checking method & Countermeasure
Check water leaking of humidifier and
clogging of drain pan.
Check operations of drain pump.
Measure resistance of indirect heater of
drain sensor.
(Normal: Approx. 82Ω between 1-3 of
CN50)
Indoor board trouble if no other problems
is detected.
Check resistance of thermistor.
0°C : 15kΩ 10°C : 9.7kΩ
20°C : 6.4kΩ 30°C : 4.3kΩ
Check contact of connector.
Indoor port trouble if no other problem is
detected.
Check drain pump operations.
Check connect contact.
Check float switch operations.
Check the thermistor's resistance.
Check the temperature picked up by
the sensor using the LED monitor.