External Fault

What does EPF mean?

An external fault has been triggered, typically by a digital input signal from an external safety device or process interlock. This indicates a condition outside the drive's internal control that requires attention, such as an emergency stop, a limit switch activation, or another process safety interlock. The drive will stop operation to ensure safety.

• Digital input (e.g., DI1, DI2) configured as 'External Fault' (e.g., Parameter P2-01 = 9) has changed state unexpectedly.
• External safety device (e.g., emergency stop, limit switch, motor thermal overload) has tripped.
• Wiring fault (e.g., broken wire, loose connection) on the external fault input circuit.
• Incorrectly configured external fault input logic (e.g., normally open vs. normally closed) in drive parameters.
• Auxiliary contact on a motor starter or protection device has opened, signaling a fault condition.

Click steps to track your progress.

1. 1

   1. Identify which digital input (e.g., DI1, DI2) is configured as the external fault source (e.g., check Parameter P2-01, P2-02).

2. 2

   2. Measure voltage across the identified digital input and its common terminal (e.g., DI1 to COM) to verify its current state.

3. 3

   3. Inspect all external devices wired to the fault input for their status (e.g., emergency stop button not pressed, overload relay reset).

4. 4

   4. Check continuity of the wiring from the drive's digital input to the external fault device using a multimeter.

5. 5

   5. Verify the external fault input configuration (e.g., normally open/closed) in the drive parameters matches the external device's output.