External Fault

What does EF4 mean?

This fault indicates that an external protective device or interlock connected to a specific digital input (corresponding to EF4) 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 protective device (e.g., level sensor, limit switch) connected to EF4 input has opened.
• Broken or loose wire connection to the digital input terminal assigned as EF4 (e.g., S4).
• External device connected to EF4 has truly detected an abnormal condition (e.g., material jam, over-temperature).
• Erroneous signal from a faulty sensor or switch wired to the EF4 input.
• Incorrect digital input logic (NO/NC) setting in the inverter parameter for the EF4 function.

Click steps to track your progress.

1. 1

   Determine which external device corresponds to the EF4 input via control schematics.

2. 2

   Check the status of the external device (e.g., limit switch position, sensor output).

3. 3

   Measure the voltage potential at the inverter's EF4 input terminal (e.g., S4) relative to the common (SC) to confirm input state.

4. 4

   Inspect the wiring path from the external device to the EF4 input for damage or secure connections.

5. 5

   Temporarily disconnect the EF4 input wire from the terminal and measure continuity across the external device's contacts.