Kaisai KMK-60RY1, Service Manual

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M thermal Split
74 202004
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4.16 P1 Troubleshooting
Digital display output 4.16.1
Description 4.16.2

Discharge pipe high pressure protection. When the discharge pressure rises above 4.3MPa, the system displays
P1 protection and Split stops running. When the discharge pressure falls below 3.6MPa, P1 is removed and normal
operation resumes.

Error code is displayed on outdoor unit main PCB and user interface.
Possible causes 4.16.3

Pressure sensor/switch not connected properly or has malfunctioned.

Excess refrigerant.

System contains air or nitrogen.

High pressure side blockage.

Poor condenser heat exchange.

Outdoor unit main PCB damaged.
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Procedure 4.16.4
P1
High pressure switch connection or
pressure sensor connection on outdoor
unit main PCB is loose
1
Yes
Ensure the pressure switch is connected
properly
No
Pressure sensor has short-circuited or
failed
2
Yes
Replace the pressure sensor
No
The high pressure side is blocked, caused
by crushed or bent pipe or blocked EXV
3
Yes
Inspect the system and fix the error
No
The heat exchange is poor
4
Yes
Inspect the system and fix the error
No
The water flow rate is not sufficient in
cooling mode
5
Yes
Inspect the water system and fix the
error
No
Replace outdoor main PCB
Notes:
1. High pressure switch connection is port CN13 on the KHA-06(08,10)RY1 outdoor unit refrigerant system main PCB (labeled 16 in Figure 4-2.2 in
Part4, 2.3 "Main PCB for Refrigerant System, Inverter Module"). port CN31 on the KHA-12(14,16)RY3 outdoor unit refrigerant system main PCB (labeled
20 in Figure 4-2.4 in Part 4, 2. 3 "Main PCB for Refrigerant System, Inverter Module").
2. Measure the resistance among the three terminals of the pressure sensor. If the resistance is of the order of mega Ohms or infinite, the pressure
sensor has failed.
3. High pressure side blockage causes discharge temperature to be higher than normal, discharge pressure to be higher than normal and suction pressure
to be lower than normal.
4. In heating mode check water side heat exchanger, water piping, circulator pumps and water flow switch for dirt/blockages. In cooling mode check air
side heat exchanger, fan(s) and air outlets for dirt/blockages.
5. Check water pressure on the manometer. If the water pressure is not > 1 bar, water flow is insufficient. Refer to Figure 2-1.9 in Part 2, 1.2 “Hydronic
Box Layout”.
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