Mitsubishi HVAC Unit PUZ-A42NHA3

Verify installation and connections

Measure impedance between ground and power supply terminal block (L1, L2) on outdoor unit

Ensure 500V Megger is not used on indoor/outdoor connecting wire terminal block (S1, S2, S3) and remote controller terminal block (1, 2)

Ensure test run switch (SW4) is set to OFF before turning on power supply

Turn on power supply 12 hours before test run to protect compressor

Ensure there is no abnormality in the outdoor unit other than specified abnormalities.

Are there any error codes other than the specified ones?

Set the emergency operation switch (SWE) on the indoor controller board.

Acknowledge that the air-conditioner will operate continuously and cannot be controlled by remote or temperature settings.

Will emergency heating operation be performed for an extended period?

Will emergency cooling operation exceed 10 hours?