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Carrier service manual
R410A DC Inverter Series
Troubleshooting
177
4.13 xP3: Compressor current protection (Display on faulty unit, all the ODU in standby)
P3: Current protection of inverter compressor
When the current of inverter compressor is too high (E655
>
35A
,
E405
>
20A), the system will display P3
protection, all the ODU in standby. When the current goes back to normal range, P3 disappear and normal
operation resumes.
Note:
1. The phenomenon of the indoor load is too large
①
:
The suction temperature and discharge temperature are both higher than normal value.
2. The phenomenon of The high pressure side of the system is blocked
②
:
The high pressure is higher than normal value, the low pressure is lower than normal value, and the discharge temperature is
higher than normal value.
3. The phenomenon of the refrigerant is excess
③
:
The high pressure is higher than normal value, the low pressure is higher than normal value, and the discharge temperature is
lower than normal value.
4. The phenomenon of the system contains air or nitrogen
④
:
The high pressure is higher than normal value, current is larger than normal value, discharge temperature is higher than
normal value, compressor makes noise, pressure meter do not display steady.
5. How to check whether compressor is error
⑤
:
Measure the resistance between two terminals among the three terminals of compressor. The resistance between two
terminals is 2-5Ω, the resistance between each terminal and ground is infinity, if the resistance is out of the normal range, the
compressor is error.
*The normal system running parameters please refer to attached table 3.
xP3: Compressor current protection
The indoor load is too large
①
Make sure the ratio of connectable
IDU is less than 130% or add ODU
No
Yes
The heat exchange of condenser
is not good. It may be caused by
dirty heat changer, abnormal ODU
fan running, ODU are too near to
each other, etc.
Check the system and
fixed up the error
No
Yes
The high pressure side of the system is
blocked
②
for squashed pipe, blocked
valve or closed stop valve
Make sure all valves are open,
check the system, and remove
the obstacle
Refrigerant is excess
③
Discharge part of the refrigerant. Add
some oil if it leaks during the discharge
System contains air or nitrogen
④
Discharge the entire refrigerant. Then
vacuum the system and refill the refrigerant.
Add oil to the system if it leaks.
Yes
No
No
Yes
Yes
High voltage short circuit or
compressor error
⑤
Make sure the high voltage circuit is normal,
or replace the compressor
Yes
No
Outdoor main control board
is damaged
No
Replace the outdoor main control board