Issue: Self Diagnostic trip and External Neutral CT disconnected alarm
Product Line: Circuit Breakers
Environment: Masterpact MTZ, Micrologic X, Xi control unit

Resolution:
Self-diagnostic trip without trip code

OR
Self-diagnostic trip with 0x6407 code


AND
Go into alarm history and see if you also have a ENCT disconnected alarm.


Do not replace the control unit.

1. There may be an intermittent connection in the eNCT metering chain. Check continuity and stable resistance values in the eNCT metering chain (T1-T2 jumper,  wiggle the wago and  wago wires, eNCT harness, eNCT)
2. If the breaker does not have the eNCT installed. The T1-T2 Jumper may be missing.
3. The eNCT wiring harness may be missing.
4. The breaker may be racked out of the cradle and therefore is disconnected from the eNCT

Check the eNCT declaration in the control unit display
If there is no eNCT installed, the eNCT declaration should be set to "NO"
If there is an eNCT installed, normally the eNCT declaration is set to "YES".  The declaration can be set to "NO" to disable the self diagnostic on the eNCT circuit.  However, it also turns off the displayed neutral current and neutral protection, but the neutral measurement will still be included in the ground fault calculation and GF will still operate normally.

Control Unit navigation path to ENCT declaration:
Home button
Configuration
Measures
System type

Released for:Schneider Electric Nigeria