Carrier 40MAHB Series Service Manual page 27

40MAHB: Service Manual
DIAGNOSIS AND SOLUTION (CONT)
Current Overload Protection (PC08)
Description: An abnormal current rise is detected by checking the specified detection circuit.
Recommended parts to repair:
• Communication wires
• Reactor
• Outdoor fan
• Outdoor PCB
Troubleshooting
Was the protection activated
While the unit is in standby mode,
verify that the voltage is between
P and N, is around DC 310V, 340V or 380V?
Is the outdoor unit's ventilation
Is the outdoor fan working normally?
Is the heat exchanger dirty?
Replace the outdoor main board.
Does the problem still exist?
Is the system pressure too high?
Check whether the refrigerant
system is running normally.
NOTE: For certain models, the outdoor PCB can not be removed separately. In the case, the outdoor electric control box should be replaced
as a whole.
Manufacturer reserves the right to change, at any time, specifications and designs without notice and without obligations.
in standby mode?
No
No
Is the power voltage normal?
Yes
Is the power voltage normal?
No
Yes
Is the voltage between
No
L and N normal?
Yes
Yes
Is the current normal?
No
Power on and measure the
voltage between P and N.
When starting the unit,
is it in the 220V~400V range?
Yes
Is the outdoor ambient
Yes
temperature higher
than 50°C?
No
Ensure that the outdoor unit's
No
ventilationis working normally.
working normally?
Yes
Refer to the solution of the
"Fan Speed is operating outsode of
No
the Normal Range" malfunction.
Yes
Yes Clean the heat exchanger.
No
Yes
Yes
No
Restart the unit when the
power supply returns to normal.
Is the power wiring Reconnect the
wired correctly? power wiring.
Are the L and N
Reconnect L and N.
wired properly?
Replace the outoor main PCB.
Is the reactor wiring
No
properly wired?
Yes
Stop the unit.
Are the reactor and
inductance functioning
normally?
Yes
Recycle the
overcharged refrigerant
27
Yes
No Reconnect the wiring.
No Replace the reactor.