26
Check code
Abnormal point and detection method
Judgment and action
Case
P6
(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 liner expansion
valve
(2) Over heating protection
<Heating mode>
1
Reduced water flow
· Clogged filter
· Leakage of water
2
High temperature
· Over-load
· Inlet water is too warm.
3
Defective water pump
4
Overcharge of refrigerant
5
Defective refrigerant circuit
(clogs)
6
Malfunction of liner 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".
(2) Over heating protection
<Heating mode>
12
Check water piping.
3
Check water pump.
45
Check operating condition of refrigerant
circuit.
6
Check liner expansion valve.
P8
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
TH32–TH6
[
0
:
and
Compressor operation frequency is 61 Hz or more.
2. Heating mode
T
63HS
–TH32
[
2
:
and
TH6–TH32
[
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
TH32: 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.
Ambient temperature (TH7)
−19
stage-g
stage-f
stage-e
stage-d
stage-c
stage-b
stage-a
−18
−16 −15
−13 −12
−11 −10
−8
−7
−3 −2
[
:
]
Tcond
63
61
59
57
54
51
48
stage-a stage-b stage-c stage-d stage-e stage-f stage-g
Tcond
stage-s
27
28
stage-s
61
Freezing/overheating protection is working
(1) Freezing protection
<Cooling mode>
Abnormal if plate heat exchanger pipe
temperature thermistor (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 operation frequency is
minimum for 5 minutes after compressor
starts operating for 6 minutes.
<Heating mode>
Abnormal if inlet water temperature
thermistor (TH32) is 15
:
or lower,
and the following condition (1 or 2) are
detected.
1. 1 minute has passed since defrosting
operation started and plate heat
exchanger pipe temperature thermistor
(TH6)•stays•at•−6
:
or lower for
continuously 30 seconds.
2. During defrosting operation and plate
heat exchanger pipe temperature
thermistor•(TH6)•stays•at•−16
:
or
lower for continuously 10 seconds.
(2) Overheating protection <Heating mode>
Abnormal if condensing temperature of
pressure sensor (63HS) detects
Tcond.
:
or more and compressor
operation frequency is less than or equal
to 30 Hz. Detection is inoperative during
defrosting.
OCH465D
