Short-time and ground-fault delays are zero due to missing ZSI jumper

What does Jumper missing for ZSI mean?

If the circuit breaker is equipped for ZSI protection but the protection function is not used, a jumper must be installed. Without it, the short-time and ground-fault tripping delays will be set to zero, preventing proper discrimination.

• The required jumper for ZSI protection has not been installed.
• Circuit breaker is configured for ZSI but the function is not intended to be used.

Click steps to track your progress.

1. 1

   Ensure the protection function is not used on circuit breakers equipped for ZSI.

2. 2

   Install a jumper to short terminals Z3, Z4, and Z5.

3. 3

   Verify the jumper is securely in place.

4. 4

   Check the trip unit settings to confirm delays are now active.