P2: Low Pressure Protection - Midea LRSJF-V120 Technical Manual

MCAC-RTSM-2012-07
H. "P2": Low pressure protection
Outdoor Unit
Display
Error
Explanation
Supposed
Causes
Troubleshooting
P2: Low pressure protection (R22 refrigerant system protects
at 0.03Mpa, recovers at 0.1MPa; R410 refrigerant system
protects at 0.05MPa, recovers at 0.15MPa, or protects at
0.14MPa, recovers at 0.3MPa).
Refrigerant is not enough or the
system leaks refrigerant.
System's gas side is blocked. Phenomenon
may be discharge temperature is high, low
pressure is low, current is small. These are
caused by closed EXV valve, closed stop valve
or blocked filter.
Heat exchanger of IDU is inefficient, which
may be caused by the dirty exchanger or
filter, block of air flow, the fan not running
or running too slowly.
Chip is defective or incorrectly installed. Or
the low pressure sensor is disconnected.
Main control board is defective.
P2
The protection device circuit checks continuity in low pressure switch
1. Faulty low pressure switch
2. Refrigerant is not enough.
3. Refrigerant does not loop smoothly.
4. Efficiency of indoor heat exchange is low.
5. Control board is not defective.
M-thermal Technical Manual (part 4)
Add refrigerant or
fix up the system.
Clear away the
block.
Clean the filter. If the
system is block by ice, the
system should also be clean.
Check the system
over and eliminate
the obstacles.
Reinstall the chip or replace it
with a fine one.
Replace the main
control board.