Mitsubishi Electric PUHZ-W112VAA 11.2kW Mono, Руководство по обслуживанию

Страница: 22 / 72

22
OCH681
Abnormal point and detection method Judgment and action
Cause
P8
P6
Check code
Freezing/overheating protection is working
(1) Freezing protection
<Cooling mode>
Abnormal if plate heat exchanger pipe
temperature (TH6) stays at −5
:
or
lower for 10 seconds or abnormal if
plate heat exchanger pipe thermistor
(TH6) stays at
−2
:
or lower and compressor opera-
tion frequency is minimum for 5 min-
utes after compressor starts operating
for 6 minutes.
<Heating mode>
Abnormal if inlet water temperature
thermistor (TH34) is 15
:
or lower,
and the following condition (1 or 2) are
detected.
1. 1 minute has passed since defrost-
ing operation started and plate heat
exchanger pipe temperature thermistor
(TH6) stays at −6
:
or lower for con-
tinuously 30 seconds.
2. During defrosting operation and plate
heat exchanger pipe temperature ther-
mistor (TH6) stays at −16
:
or lower for
continuously 10 seconds.
(1) Freezing protection
<Cooling mode>
1
Reduced water flow
· Clogged filter
· Leakage of water
2
Low temperature
· Low-load
· Inlet water is too cold.
3
Defective water pump
4
Defective outdoor fan control
5
Overcharge of refrigerant
6
Defective refrigerant circuit (clogs)
7
Malfunction of linear expansion valve
<Heating mode>
1
Reduced water flow
· Clogged filter
· Leakage of water
2
Low temperature
· Low-load
· Inlet water is cold.
3
Defective water pump
4
Leakage or shortage of refrigerant
5
Malfunction of linear expansion
valve
1) Freezing protection
<Cooling mode>
12
Check water piping.
3
Check water pump.
4
Check outdoor fan motor.
5
–
7
Check operating condition of refrigerant
circuit.
7
Check linear expansion valve.
<Heating mode>
12
Check water piping.
3
Check water pump.
4
Correct to proper amount of refrigerant.
5
Check linear expansion valve. Refer to "9-5.
HOW TO CHECK THE COMPONENTS".
PE
Inlet water temperature
Abnormal if the following conditions are
detected for continuously 10 seconds.
1. Cooling mode
During compressor operation
TH34 < 3
:
2. Heating mode (exclude defrosting)
During compressor operation
TH34 < −10
:
3. Defrosting mode
During compressor operation
TH34 < 0
:
Thermistor
TH34: Inlet water temperature
1
Reduced water flow
· Clogged filter
· Leak of water
2
Low temperature
· Low-load
· Low temperature inlet water
3
Defective water pump
4
Leakage or shortage of refriger-
ant
12
Check water piping.
3
Check water pump.
4
Check intake superheat.
Check leakage of refrigerant.
Pipe temperature
Abnormal if the following conditions are
detected for continuously 3 minutes after
compressor starts operating for 10 minutes.
1. Cooling mode
T
63HS
–TH7
[
2
:
and
TH3–TH7
[
4
:
or T
63HS
−TH3 < 0
:
and
TH34–TH6
[
0
:
and
Compressor operation frequency is 61 Hz or more.
2. Heating mode
T
63HS
–TH34
[
2
:
and
TH6–TH34
[
1
:
and
TH7–TH3
[
1
:
and
Compressor operation frequency is 61 Hz or more.
T
63HS
: Condensing temperature of pressure
sensor (63HS)
Thermistor
TH3: Liquid temperature
TH34: Inlet water temperature
TH6: Plate HEX Liquid temperature
TH7: Ambient temperature
1
Leakage or shortage of
refrigerant
2
Malfunction of linear expansion
valve
3
Refrigerant circuit is clogged
with foreign objects.
Note: Clogging occurs in the
parts which become below
freezing point when water
enters in refrigerant circuit.
4
Disconnection of thermistor
holder.
1
Check intake superheat.
Check leakage of refrigerant.
2
Check linear expansion valve.
3
After recovering refrigerant, remove water
from entire refrigerant circuit under vacuum
more than 1 hour.
4
Check temperature display on outdoor
controller circuit board.
Temperature display is indicated by setting
SW2 of outdoor controller circuit board.
Check the holder of thermistor.