External Fault at Terminal S8

What does EF8 mean?

This fault is triggered when an external condition connected to multi-function digital input terminal S8 activates the Drive's external fault function, causing the Drive to stop. It indicates an issue with the external device or process monitored by S8, which could lead to machine downtime or safety risks if misidentified.

• An external sensor, switch, or safety device connected to terminal S8 has triggered its fault state.
• Physical damage to the wiring or insulation breakdown leading to an unwanted signal change at S8.
• Parameter H1-08 (S8 function selection) is incorrectly set, causing the Drive to misinterpret the input signal as a fault.
• Transient voltage or electromagnetic interference (EMI) on the control circuit influencing the S8 input.
• Failure of the external device itself, providing a constant or intermittent fault signal.

Click steps to track your progress.

1. 1

   Identify the external device whose signal is wired to terminal S8 by checking the H1-08 parameter.

2. 2

   Measure the voltage at terminal S8 relative to SN using a multimeter to confirm its current input state.

3. 3

   Verify that parameter H1-08 is programmed for 'External Fault' and that the contact type (N.O. or N.C.) matches the external device.

4. 4

   Carefully inspect the entire wiring path from terminal S8 to the external device for secure connections and absence of damage.

5. 5

   Temporarily bypass the external switch by shorting S8 to SN (for N.O. input) or opening the circuit (for N.C. input) to isolate the fault source (ENSURE SAFETY).