Airwell johnson JOAU-ZCY218-H11, Service Manual

Page: 113 / 124

Troubleshooting
Electrical Control System 113
2.4.2.6 Low pressure protection (ODU P2) (For JOAU-ZCY430-H11, JOAU-ZCY536-H11)
Low pressure protection
Judge 1: Whether the
wiring between the low
pressure protector and main
control board is connected
well or correctly
Method: Short connect the
low pressure protector
socket, check whether the
system can run normally
Yes
No
Connect it well
Replace outdoor main board
No
Replace low pressure protector Yes
Judge 2: Whether
the low pressure
protector is broken
Check whether
the refrigerant
system is ok
Judge 3: Check whether the
outdoor ambient
temperature is too low
No
Stop the unit Yes
Method: Connect the pressure
gauge to the gauge joint of the
system, check whether the
pressure is lower than
0.14MPa
No
Leak hunting: Charge nitrogen or refrigerant
to the system, if the leakage is serious, there
will be distinct gas leakage “cici” sound; if the
leakage is slight, use the suds (mixture of
water and abluent is also ok if it can make
bubble) or electronic leak detector.
Yes
Judge 5: The refrigerant
pipe is blocked
No
Let the refrigerant out, then use the high
pressure nitrogen or refrigerant to blow pipe,
vacuumize and charge the refrigerant again
Yes
Judge 4: The
refrigerant of the
system is leakage