Kaisai KMK-60RY1, Service Manual

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M thermal Split
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4.18 P4 Troubleshooting
Digital display output 4.18.1
Description 4.18.2

Discharge temperature protection.

When the compressor the discharge temperature rises above 115°C, the system displays P4 protection and Split
stops running. When the discharge temperature falls below 95°C , P4 is removed and normal operation resumes.

Error code is displayed on refrigerant system main PCB and user interface.
Possible causes 4.18.3

Temperature sensor error

High pressure side blockage.

Poor condenser heat exchange.

Outdoor unit main PCB damaged.
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Procedure 4.18.4
P4
Discharge pipe temperature sensor
connection on outdoor unit main PCB is
loose
1
Yes
Ensure the temperature sensor is
connected properly
No
Final outlet water temperature sensor
connection, domestic hot water tank
temperature sensor connection or water
side heat exchanger water outlet
temperature sensor connection on
hydronic box main PCB is loose
2
Yes
Ensure the temperature sensor is
connected properly
No
Temperature sensor has short-circuited
or failed
3
Yes
Replace the sensor
No
High pressure switch connection or
pressure sensor connection on outdoor
unit main PCB is loose
4
Yes
Ensure the pressure switch is connected
properly
No
Pressure sensor has short-circuited or
failed
5
Yes
Replace the pressure sensor
No
The high pressure side is blocked, caused
by crushed or bent pipe or blocked EXV
4
Yes
Inspect the system and fix the error
No
The condenser heat exchange is poor in
heating mode
5
Yes
Inspect the system and fix the error
No
The water flow rate is not sufficient in
cooling mode
6
Yes
Inspect the water system and fix the
error
No
Replace outdoor main PCB
Notes:
1.
Discharge pipe temperature sensor connection is port CN8 on the KHA-06(08,10)RY1 outdoor unit refrigerant system main PCB (labeled 15 in
Figure 4-2.2 in Part4, 2.3 "Main PCB for Refrigerant System, Inverter Module").
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