Error Code: EC 07 – Outdoor Fan Speed Out of Control

Error Code: EC 07 – Outdoor Fan Speed Out of Control

What this means:
The outdoor unit has detected that the fan speed is consistently too low or too high outside normal operating range. When this occurs for a set time, the system stops and shows the EC 07 error. This may be caused by motor issues, wiring faults, or a failing PCB.

Try this first (quick reset):

1. Turn off power to the system completely.

2. Wait 2 full minutes.

3. Turn the unit back on and observe the fan operation.

• If fan speed stabilizes — the system resumes normally.

• If the error returns — proceed to further checks.

Next steps (for technicians):

1. Spin the fan manually with power off:

   • If it doesn’t spin freely → check for obstructions or mechanical failure.

2. Check the fan motor wiring:

   • If miswired or damaged → ensure proper and secure connections.

3. Measure voltage from the PCB to fan motor (for motors with internal chips):

   • Red (Pin 1) to Black (Pin 3): 192–380V

   • White (Pin 4) to Black (Pin 3): 13.5–16.5V

   • Yellow (Pin 5): 0–6.5V (Vsp signal)

   • If voltages are out of range → replace the main PCB.

4. If motor has UVW terminals (chip in PCB):

   • Measure resistance between U–V, U–W, and V–W.

   • If resistance is unequal → replace the fan motor.

   • If resistance is normal and voltage is correct → replace the PCB.

What you might need:

• Outdoor fan motor

• Fan assembly

• Outdoor PCB

• DC fan IPM board (if applicable)

• Connection wires

Helpful tip:
Always perform a manual fan spin test before diving into voltage or resistance checks. Many EC 07 issues are caused by simple motor jamming or worn bearings.

Click here to view the detailed guide.TS21