Midea MHC-96HWD1N1(A) Service Manual page 46

R410A Full DC Inverter Split Duct Type Technical Manual

P1: High temperature protection or high temperature protection of discharge sensor
P1: High pressure
protection
The heat exchange of condenser is
not good. It may be caused by dirty
heat changer, abnormal ODU fan
running, ODU are too near to each
other, etc.
No
The high pressure side of the system
is blocked for squashed pipe,
blocked valve or closed stop valve
No
Refrigerant is excess
No
System contains air or nitrogen
No
Outdoor main control
board is damaged

P2: Low pressure protection
P2/H5: Low pressure protection
System is lack of refrigerant.
(Refrigerant recharging is not
according to the requirement,
or there has refrigerant
leakage)
No
The low pressure side is blocked for
squashed pipe, closed EXV, closed
strop valve, dirty filter, etc.
No
The heat exchange of evaporator
is not good. It may be caused by
dirty heat changer, abnormal IDU
fan running, some barrier in front
of the air outlet, etc.
No
Outdoor main control
board is damaged
45
Yes
Check the system and
fixed up the error
Make sure all valves are
Yes
open, check the system, and
remove the obstacle
Discharge part of the refrigerant. Add
Yes
some oil if it leaks during the discharge
Discharge the entire refrigerant. Then
Yes
vacuum the system and refill the
refrigerant. Add oil to the system if it leaks.
Yes
Add refrigerant or check up
the leakage of the system
Make sure all valves are open, clean
Yes
the filter, if the filter is blocked by ice,
the system should be clean
Yes
Check the system and
fixed up the error
MCAC-UTSM-201503
Replace the outdoor
main control board
Replace the outdoor
main control board