External Fault

What does EF8 mean?

This fault indicates that an external protective device or interlock connected to a specific digital input (corresponding to EF8) 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.

• Safety relay output contact or emergency stop circuit connected to EF8 has opened.
• Damage to the control wiring connecting the external safety device to the EF8 input (e.g., S8).
• Faulty external safety device that is incorrectly reporting a trip condition.
• Incorrect assignment or configuration of the digital input function for EF8 (e.g., P0-11) within inverter parameters.
• Insufficient auxiliary power supply (e.g., 24VDC) for the external device connected to EF8, causing it to de-energize.

Click steps to track your progress.

1. 1

   Locate the external safety relay or E-stop button whose output is wired to the EF8 input terminal (S8).

2. 2

   Verify the status of the safety relay (e.g., green/red LEDs) and ensure E-stop buttons are reset.

3. 3

   Measure the voltage between the S8 input terminal and the common terminal (SC) to confirm the input state.

4. 4

   Check for continuity of the wires running from the safety device's output contacts to the inverter's S8 terminal.

5. 5

   If applicable, verify the external device's 24VDC power supply is present and stable.