Carrier 38MGR Series - DIAGNOSIS AND SOLUTION: VOLTAGE PROTECTION; Voltage Protection Error (E5)

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