H H Check Of Hps; I I The Other Cases - Mitsubishi Electric MXZ-2A40VA Service Manual

• When the operation frequency does not go up from lowest frequency.

H H Check of HPS

MXZ-4A80VA
1. Disconnect the connector CN681 in the electronic control P.C. board.
2. Check the resistance of HPS after 1 minutes have passed since the outdoor unit power supply was turned off.
Check the resistance between
each terminal.
0"
Reconnect CN681.
Turn on power supply to the indoor and outdoor unit.
3 minutes later, starts EMERGENCY OPERATION.
Yes
Is HPS protection displayed
immediately after compressor
starts?
Yes
Normal

I I The other cases

Indoor unit dose not operate. (different operating models in multisystem)
• When you try to run two indoor unit simultaneously, one for cooling and the other for heating, the unit which
transmits signal to the outdoor units earlier decides the operation mode. The other unit indicates as shown in
the figure below.
• When the above situation occurs, set all the indoor units to the same mode, turn OFF the indoor units, and
then turn them back ON.
• Though the top of the indoor unit sometimes gets warm, this does not mean malfunction. The reason is that
the refrigerant gas continuously flows into the indoor unit even while it is not operating.
OPERATION INDICATOR
Infinity
Replace HPS.
No
Replace the electronic control P.C. board.
Lighting
70
Blinking