MUZ-GE - Testing Outdoor Fan

Mitsubishi MUZ-GE

Re: Test Outdoor Fan Motor

The unit uses a DCV 3-Phase fan motor.

1. Test Winding Resistance

• Disconnect power to the outdoor unit.
• Wait at least 30 seconds for the capacitors to discharge.
• Disconnect the leads to the fan motor (Red, White & Blk).
• Test resistance across the motor windings.

2. Test Motor Bearings

• Disconnect power to the outdoor unit.
• Wait at least 30 seconds for the capacitors to discharge.
• Rotate the fan blade manually.
• The motor should rotate smoothly.
• Test resistance across the motor windings.

3. Test Motor Feedback

• Disconnect power to the outdoor unit.
• Wait at least 30 seconds for the capacitors to discharge.
• Disconnect CN931 and CN932 from the Inverter P.C. Board
• Turn on power to the unit.
• On CN931, check DC voltage across the pins as you manually rotate the motor.
  • Between 1(+) and 5(-)
  • Between 2(+) and 5(-)
  • Between 3(+) and 5(-)
• DC voltage should alternate between 0 and 5 vdc.