Set-value encoder at 4mA...20mA defective

What does Sd5 mean?

This fault indicates a problem with a 4-20mA current loop signal used as a set-value input, likely from an encoder or other process sensor. This could be due to an open circuit, short circuit, or the signal source being faulty. By default, this critical condition triggers a full TRIP, inhibiting all ignition pulses and resetting the Ready signal, as a lost or incorrect set-value can lead to uncontrolled operation. Manual reset is required.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Measure loop current: Use a multimeter in series to measure the current in the 4-20mA loop and ensure it is within the expected range.

2. 4

   Check for external interference: Ensure the signal cable is properly shielded and routed away from power cables to prevent electrical noise.

3. 5

   Verify drive input impedance: Confirm the drive's analog input is correctly configured for a current input.