How to perform Zone-Selective Interlocking (ZSI) test for MTZ breakers using EPC and determine pass/fail?


04 January 2022

For Australian customers,
EcoStruxure Power Commission (EPC) software ‘Circuit Breaker Advanced Testing’ paid subscription is required to perform ZSI test. Please contact your Schneider sales rep for more details about the subscription.

Please see the attached steps given in the EPC Help for Zone-Selective Interlocking Test. 

- Firstly, you need to add both downstream and upstream breakers to EPC project. 
  Please see this FAQ video for more details on adding devices to EPC project.

- Connect the downstream device through USB cable to your PC

- Click on the ‘Connect To Device’ and it will indicate it’s connected in ‘Direct’.

- Then click on ‘Zone-selective Interlocking Test’

- Then on the ZSI screen you need to select the upstream breakers to run the test.

- Now click the ‘Run Test’ button.
(Please see attached example video showing the process with two MTZ breakers)

The result of the test is decided by looking at the Isd/Ii and/or Ig trip indicator LED status of the upstream breaker.
- If ground-fault protection is configured for ZSI**, Ig trip indicator LED will flash.
- If short-time protection is configured for ZSI**, Isd/Ii trip indicator LED will flash.
- If both ground-fault and short-time protection are configured for ZSI**, both Ig and Isd/Ii trip indicator LEDs will flash.
(See attached example video showing how both LEDs flash on a Micrologic X.)

(**Please see the screenshot at the end of the FAQ showing an example ZSI setting page)

- Then you can click on the green right tick mark, if the relevant LED/s is/are flashing on the upstream breaker to indicate that the test is passed. 

- If any LED does not flash on the upstream breaker the user can select red cross icon which indicates that the test has failed.

Example ZSI setting page for MTZ breakers in EPC: