External Fault

What does EF3 mean?

This fault indicates that an external protective device or interlock connected to a specific digital input (corresponding to EF3) has been activated, triggering a trip in the inverter. The specific cause depends on the external device wired to that input. This is a safety feature to stop the drive based on external process conditions, preventing damage to the system or injury.

• Normally Closed (NC) contact of an external safety device (e.g., overload relay, pressure switch) connected to EF3 input has opened.
• Normally Open (NO) contact of an external protective device connected to EF3 input has failed to close when required.
• Wiring fault (e.g., broken wire, loose terminal) in the circuit connected to the digital input assigned as EF3.
• External device itself has tripped (e.g., motor thermal overload, guard door open).
• Incorrect programming of the digital input function for EF3 (e.g., P0-04, P0-05 assigning input function).

Click steps to track your progress.

1. 1

   Identify the specific external device connected to the digital input assigned as EF3 (e.g., using wiring diagrams).

2. 2

   Measure voltage across the EF3 input terminal (e.g., S3) and the common terminal (SC) to determine its state (e.g., 0V or 24VDC).

3. 3

   Inspect the external protective device for its trip status indicator and reset if possible.

4. 4

   Check continuity of the wiring from the external device's contacts to the inverter's EF3 input terminal.

5. 5

   Bypass the external device momentarily (for testing purposes ONLY, with safety precautions) to confirm the inverter clears the fault.