Safety Circuit Fault (Input Open)

What does Safety circuit fault mean?

This fault occurs when the safety circuit input terminals (across S1 and PC, or across S2 and PC) are detected as open. This indicates a break in the safety loop, signaling a potentially unsafe condition and leading to inverter shutdown. It could be due to incorrect wiring, a fault in an external safety device, or an activated safety interlock.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Verify that the external safety stop input signal source (e.g., safety relay module or safety device) is operating properly and its contacts are closed.

2. 4

   Refer to the Safety stop function instruction manual (BCN-A211508-000) for detailed troubleshooting guidance related to safety inputs.