Carrier 40QSM009DS Service Manual page 106

16.3.8 Over voltage or too low voltage protection diagnosis and solution (P1)
Error Code
Malfunction conditions
Potential causes
Trouble shooting:
Check the power supply. Is it
in working order?
Yes
Check the connections and
w i r e s . Are they in working
order?
Yes
Turn power on and while the unit is on
standby, check if the voltage between P
and N is at DC 310V, 340V or 380V?
Then start up the unit and measure the
voltage between P and N. Is it in now
between 220V~400V?
Yes
Check the reactor. Is it in
working order?
Yes
Replace the reactor
P1
Abnormal increases or decreases in voltage are detected by
checking the specified voltage detection circuit.
Power supply issues
●
System leakage or blockage
●
Faulty PCB
●
No
No
No
No
103
Turn off the unit
Ensure proper connections or
replace the wires
Replace the IPM board
Replace outdoor main PCB
Remark:
Measure the DC voltage
between P and N port.
The normal value should
be around 310V.340V or
380V