R410A DC Inverter VRF V4 Plus W Series 50Hz
MCAC-VTSM-2016-04
208 Troubleshooting
3.9 P0: Top temperature protection of inverter compressor; P4: Discharge temperature protection; H6:
P4 protection appears three times in 100 minutes
H6 error cannot resume automatically, and it can resume only by restarting the machine.
Note:
1. How to check whether the discharge temperature sensor is short circuit or disabled
①
:
Using a multi meter to measure resistance, if the resistance is too small, the sensor is short circuit, if the resistance in certain
temperature is not consistent with attached table 2, the sensor is disabled
2. The phenomenon of lack of refrigerant
②
:
Top temperature and discharge temperature of all compressors are higher than normal value, discharge pressure and suction
pressure are both lower than normal value, current is lower than normal value, suction pipe may be frosting. All the phenomenon
will disappear after recharging refrigerant.
3. The phenomenon of the low pressure side is blocked
③
:
The discharge temperature is higher than normal value*, low pressure is lower than normal value*, current is lower than normal
value* and suction pipe may be frosting.
4. The phenomenon of the indoor load is too large
④
:
The suction temperature and discharge temperature are both higher than normal value.
5. The phenomenon of the system contains air or nitrogen
⑤
:
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.
*The normal system running parameters please refer to attached table 3.
P0/P4/H6
System is lack of refrigerant
②
.
(Refrigerant recharging is not
according to the requirement,
or there has refrigerant
leakage)
Add refrigerant or check up
the leakage of the system
The low pressure side is blocked
③
for squashed pipe, closed EXV,
closed stop valve, dirty filter, etc.
Make sure all valves are open, clean the
filter, if the filter is blocked by ice, the
system should be clean
The indoor load is too large
④
Make sure the ratio of connectable IDU is
less than 130% or add ODU
System contains air or nitrogen
⑤
Discharge the entire refrigerant. Then vacuum
the system and refill the refrigerant. Add oil to
the system if it leaks.
Discharge temp. sensor is
short circuit or disabled
①
.
Replace the sensor
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
Outdoor main PCB
is damaged
Replace the outdoor
main PCB