Symmetra Power Array 3:1 erroneously reports "Input circuit breaker tripped open"

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Issue

Symmetra Power Array 3:1 reports that its input circuit breaker is open.

Product Line

Symmetra Power Array

Environment

3:1 models (3 phase in, 1 phase out)

Cause

Behind the lowest grill cover on Symmetra 3:1 you will find 3 switches.

Starting from left to right:
1. Switch is a 3 pole switch for the input circuit breakers of the 3 input phases.
2. Switch is the circuit breaker for the Maintenance Bypass Switch.
3. Switch is the Maintenance Bypass switch.

When starting the Symmetra you must close the input circuit breakers (the switch must be in the "up" position). You must also close (up) the circuit breaker for the Maintenance Bypass Switch. If you leave the circuit breaker for the Maintenance Bypass Switch in the open (down) position then you will get "Input Circuit Breaker tripped open" message on the PowerView. The red fault LED will also be lit on the PowerView.

The explanation is that the 3 pole input breaker Auxiliary Switch (i.e. micro-switch for position sensing) and the Maintenance Bypass Switch breaker Auxiliary Switch are wired in series. This makes the logic equivalence of an AND. Both breakers, the 3 pole input AND Maintenance Bypass Switch need to be closed for the MIM to declare them normal.

Resolution

To clear this message, push the 3 pole input circuit breaker and the circuit breaker for the Maintenance Bypass Switch to the closed or up position.