Carrier 38MGR Series Service Manual page 44

DIAGNOSIS AND SOLUTION (CONT)
Voltage protection error (E5)
ERROR CODE
MALFUNCTION DECISION
CONDITIONS
SUPPOSED CAUSES
Troubleshooting
the outdoor unit power supply.
Check if the voltage of the
IPM board P and N is normal?
DC277-356V for 18-24KBtu/h;
DC277-410V for 36KBtu/h.
Replace the IPM board, then
check whether the system
Replace outdoor main board.
44
E5
An abnormal voltage rise or drop is detected by checking the specified voltage detection circuit.
• Power supply problems
• System leakage or block
• PCB faulty
Voltage Protection
Check the voltage of
Is the voltage between
L (L1) and N (L2) about
187~253VAC.
Yes
No
Replace bridge rectifiers,
then check whether the
system can run normally
(only for four zone).
No
can run normally.
No
Specifications subject to change without notice.
No Check the power supply.
Yes
Yes
Yes
Trouble is solved.
38MGR-04SM