Midea VRF Series Service Manual page 135

V6R VRF 50/60Hz
characteristics table, the sensor has failed. Refer to Table 6-4.2 in Part 6, 4.1 "Temperature Sensor Resistance Characteristics ".
3. An insufficiency of refrigerant causes compressor discharge temperature to be higher than normal, discharge and suction pressures to be lower than normal
and compressor current to be lower than normal, and may cause frosting to occur on the suction pipe. These issues disappear once sufficient refrigerant has
been charged into the system. For abnormal refrigerant system parameters refer to Table 6-4.4 and 6-4.5 in Part 6, 4.3 "Parameters of Excess and Insufficient
Refrigerant System".
4. A low pressure side blockage causes compressor discharge temperature to be higher than normal, suction pressure to be lower than normal and compressor
current to be lower than normal, and may cause frosting to occur on the suction pipe. For abnormal refrigerant system parameters refer to Table 6-4.4 and
6-4.5 in Part 6, 4.3 "Parameters of Excess and Insufficient Refrigerant System".
5. An indoor load that is too large causes suction and discharge temperatures to be higher than normal. For abnormal refrigerant system parameters refer to
Table 6-4.4 and 6-4.5 in Part 6, 4.3 "Parameters of Excess and Insufficient Refrigerant System".
6. Air or nitrogen in the system causes discharge temperature to be higher than normal, discharge pressure to be higher than normal, compressor current to
be higher than normal, abnormal compressor noise and an unsteady pressure meter reading. For abnormal refrigerant system parameters refer to Table 6-
4.4 and 6-4.5 in Part 6, 4.3 "Parameters of Excess and Insufficient Refrigerant System".
7. In cooling mode check outdoor heat exchangers, fans and air outlets for dirt/blockages. In heating mode check indoor heat exchangers, fans and air outlets
for dirt/blockages.
134