P3/Xp7/P8: Compressor Current Protection - Midea VRF V4 Plus I Series Manual

R410A DC Inverter V4 Plus 50Hz
5.11 P3/XP7/P8: 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 over12A, 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.
P3/XP7/P8: Compressor current
protection
The indoor load is too large
No
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.
No
The high pressure side of the system is
②
blocked
valve or closed stop valve
No
Refrigerant is excess
No
System contains air or nitrogen
No
High voltage short circuit or
compressor error
No
MC9S08AC128
disabled
No
Main board is disabled
Note:
1. The phenomenon of the indoor load is too large
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
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
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
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
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.
106
①
for squashed pipe, blocked
③
④
⑤
chip is
③
:
⑤
:
Yes
Make sure the ratio of connectable
IDU is less than 130% or add ODU
Yes
Check the system and
fixed up the error
Make sure all valves are open,
Yes
check the system, and remove
the obstacle
Yes
Discharge part of the refrigerant. Add
some oil if it leaks during the discharge
Discharge the entire refrigerant. Then
Yes
vacuum the system and refill the refrigerant.
Add oil to the system if it leaks.
Yes
Make sure the high voltage circuit is normal,
or replace the compressor
Yes
Replace main board
①
:
②
:
④
:
MCAC-VTSM-2014-04
Troubleshooting