Outdoor Terminal Block Incorrect Connection
Mitsubishi Electric · PAR-21MAA MA Remote Controller
What does F1 mean?
The outdoor unit's power supply terminals (L1, L2, L3) or communication terminals (S1, S2, S3) have incorrect connections. This prevents the remote controller from operating and keeps displaying 'PLEASE WAIT'. The outdoor board LED will blink green once and red once alternately after system startup.
Repair Steps
- 1
Verify the wiring of L1, L2, L3 power supply terminals at the outdoor unit according to the system's wiring diagram.
- 2
Verify the wiring of S1, S2, S3 communication terminals between the indoor and outdoor unit for correct polarity and secure connection.
- 3
Measure insulation resistance between the ground and the power supply terminal block (L, N) on the outdoor unit using a 500V Megger; expect a reading of 1.0 MΩ or over.