MCAC-VTSM-2015-10
R410A All DC Inverter V5 X Series 50Hz
Troubleshooting 147
4.15 yHd: Slave unit malfunction (y refers to corresponding slave unit)
yHd is only displayed on the master unit. y stands for corresponding slave unit. If y is 1, it refers No.1 slave unit
which has malfunctioned.
4.16 P0: Temperature protection of inverter compressor
4.17 P4: Discharge temperature protection;
4.18 H6: P4 protection appears three times in 100 minutes
The error will only display on the faulty unit, all the ODUs will be on standby.
If H6 error occurs system must be restarted as it cannot automatically resume.
Note:
* How to check for the discharge temperature sensor
Using a multi meter to measure resistance, if the resistance is too low, the sensor has short circuited, if the resistance at certain
temperature is not consistent with attached table 2, the sensor is disabled
* The phenomenon of
insufficient refrigerant
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.
Outdoor main PCB is damaged
Replace the outdoor main PCB
P0/P4/H6
Insufficient refrigerant caused by
insufficient recharge or refrigerant
leakage*
Add refrigerant or inspect the system
for leaks
The low pressure side is blocked,
caused by crushed or bent 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 cleaned
The indoor load is too large*
Make sure the ratio of connectable
IDU is less than 130% or add ODU
System contains air or nitrogen*
Flush all refrigerant. Then vacuum
the system and recharge refrigerant.
Add oil to the system if it leaks.
Discharge temp. sensor has short
circuited or is disabled*.
Replace the sensor
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
