Xp3: Over Current Protection Of Compressor - Midea V5 X VRF Series Technical & Service Manual

R410A All DC Inverter V5 X Series 50Hz
4.22 xP3: Over current protection of compressor (When x is 1, it refers to A compressor; 2 refers to B
compressor)
When inverter compressor current is over 12A*, the system will display P3 protection, the ODU in standby.
When the current goes back to normal range, P3 disappears and normal operation resumes.
P3: Compressor over current protection
The indoor load is too large*
Low condenser heat exchange, causes may
include dirty heat exchanger, abnormal ODU
fan operation, too closed outdoors
installation, etc.
The high pressure side of the system is
blocked, caused by crushed or bent pipe,
blocked valve or closed stop valve*
Excess refrigerant*
System contains air or nitrogen*
High voltage short circuit or compressor
error*
Outdoor main PCB is damaged
Note:
* The phenomenon of too large indoor load is
The suction temperature and discharge temperature are both higher than normal value.
* The phenomenon of high pressure side blockage
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.
* The phenomenon of excess refrigerant is
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.
* The phenomenon of air or nitrogen in the system
The high pressure is higher than normal value, current is larger than normal value, discharge temperature is higher than normal
value, abnormal compressor noise, pressure meter is not steady.
* How to check for compressor
Measure the resistance between two of the three compressor terminals. The resistance between two terminals is 2-5Ω, the
resistance between each terminal and ground is infinite, if the resistance is out of the normal range, the compressor has
malfunctioned.
*The protection current of different compressors are as followed: E405DHD-36D2YG, 12A; E405DHD-42D2YG, 15A;
E655DHD-65D2YG, 21A; E705DHD-72D2YG, 23A.
150
No
No
No
No
No
No
Yes
Make sure the ratio of connectable IDU is
less than 130% or add ODU
Yes
Inspect the system and fix the error
Make sure all valves are open, ensure free
Yes
Discharge part of the refrigerant. Add oil if
Yes
it leaks during the discharge
Flush all refrigerant. Then vacuum the
Yes
system and recharge the refrigerant. Add
oil to the system if it leaks
Yes Make sure the high voltage circuit is
normal, or replace the compressor
Replace the outdoor main PCB
MCAC-VTSM-2015-10
refrigerant flow
Troubleshooting