15V supply interfered

What does U15 mean?

This fault indicates an issue with the drive's internal 15V power supply, which typically powers internal control circuitry, sensors, or external devices. By default, this critical condition triggers a full TRIP, inhibiting all ignition pulses and resetting the Ready signal, as instability in this supply can compromise the drive's internal operations and safety functions. Manual reset is required.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Measure 15V supply (if test points available): With the drive powered, if safe test points are accessible, verify the actual 15V supply output.

2. 4

   Check for short circuits: Use a multimeter in resistance mode (with power off) to check for shorts on the 15V rail if accessible.

3. 5

   Consider control board replacement: If no external cause is found, the internal 15V supply circuit on the control board may be faulty.