Carrier 38QUA009DS, Service Manual, Page: 106 / 116

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