Midea V4+R Series, Service Manual

Page: 79 / 104

V4+R VRF 50/60Hz
201608 77
P
art
5
- Di
agno
si
s and
Tr
ou
bles
ho
o
ting
4.15 P1 Troubleshooting
Digital display output 4.15.1
Description 4.15.2

Discharge pipe high pressure protection. When the discharge pressure rises above 4.4MPa, the system displays P1
protection and all units stop running. When the discharge pressure falls below 3.2MPa, P1 is removed and normal
operation resumes.

If the system has a 3-phase protector and the 3-phase protector is connected with the high pressure switch, the
system will display P1 protection when initially powered on, and P1 protection will disappear once the system reaches
a steady state.

Error code is only displayed on the unit with the error.
Possible causes 4.15.3

Outdoor unit stop valves are closed.

Pressure sensor/switch not connected properly or has malfunctioned.

Excess refrigerant.

System contains air or nitrogen.

High pressure side blockage.

Poor condenser heat exchange.

Main PCB damaged.
Procedure 4.15.4
P1
ODU stop valves are closed
Yes
Open the stop valves
No
High pressure sensor connection on main
PCB is loose
1
Yes
Ensure the sensor is connected properly
No
High pressure sensor has short-circuited
or failed
2
Yes
Replace the sensor
No
Excess refrigerant
3
Yes
Discharge part of the refrigerant. Add oil
if it leaks during discharge
No
Flowchart continued on next page …