Failures Low Breaker downstream of UPS

[joan271273]

We are have a large facility ( new) , this facility has multiple LV UPS systems made up of 750 kVA modules in parallel.

We are experiencing failures of the main output breaker of the switchboard that consolidates the UPS outputs and of the load bank breaker. The occurrence has not been constant, these failures have occurred during tests below 100% capacity. In one instance a CB failed when open with no load on the UPS ( UPS were on inverters)

Any thoughts

 

[waross]

Same as the other thread. Condensation.

Bill
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"Why not the best?"
Jimmy Carter