Power Loss

What does F3 mean?

This fault signifies a loss of incoming AC line power or a significant low voltage condition on the AC input. It indicates the drive's inability to maintain operation due to insufficient input power.

• Complete loss of one or more phases of the incoming AC line voltage (e.g., due to tripped breaker, blown fuse upstream).
• Significant voltage sag or brownout condition on the main AC power supply lasting longer than the drive's ride-through capability.
• Loose or corroded connections on the drive's input terminals (L1, L2, L3) causing an intermittent or complete loss of power.
• Failure of the internal power supply or rectifier section within the drive, preventing DC bus voltage maintenance.
• Main contactor or upstream protective device intermittently dropping out due to control circuit issues.

Click steps to track your progress.

1. 1

   Measure the incoming AC line voltage (L1-L2, L2-L3, L3-L1 for 3-phase, L1-N for 1-phase) at the drive's input terminals using a multimeter.

2. 2

   Inspect all upstream circuit breakers and fuses for tripped conditions or blown elements and reset/replace as necessary.

3. 3

   Verify the torque on the incoming AC power wiring connections to the drive's L1, L2, L3 terminals and the upstream disconnect.

4. 4

   Check for sustained voltage sags on the utility grid using a power quality meter if the fault is intermittent or occurs during heavy load transients.

5. 5

   Examine the main contactor (if present upstream of the drive) for proper coil voltage and contact integrity.