Mitsubishi Split System SUZ-AA12NLHZ-U1

Select the desired function from the table using the remote controller

Adjust the defrost finish temperature setting

Confirm the new temperature setting on the remote controller

Verify that the air conditioner responds to the new setting

Ensure that contamination of different refrigerants does not occur when using charging equipment

Ensure that hoses or lines are as short as possible to minimize the amount of refrigerant contained in them

Keep cylinders in an appropriate position according to the instructions

Ensure that the refrigerating system is earthed prior to charging the system with refrigerant

Label the system when charging is complete (if not already)

Take extreme care not to overfill the refrigerating system

Ensure capacitors are discharged safely to avoid sparking

Check for exposed live electrical components and wiring during system operations

Verify continuity of earth bonding

Is there any fault that could compromise safety?

If a fault exists, ensure no electrical supply is connected until resolved

If fault cannot be corrected immediately, implement an adequate temporary solution

Report the fault and temporary solution to the equipment owner

Is the outside temperature 68°F (20°C) or below?

Activate pre-heat control by cutting the JK wire of the inverter P.C. board

Refer to '11-6. TEST POINT DIAGRAM AND VOLTAGE' for guidance

Inverter P.C. Board Replacement

Check the Jumper wires on the new inverter P.C. board

Cut/solder Jumper wires if necessary

Ensure power is turned off to the outdoor inverter P.C. board

Gather necessary tools for cutting/soldering

Locate the JS wire on the outdoor inverter P.C. board

Determine current state of JS wire

Adjust the JS wire to change defrost finish temperature

Verify the defrost finish temperature setting