Brand new breaker bad

[solarken]

I went to turn up a solar PV system yesterday for the first time, and found the brand new Siemens QP breaker I used for backfed connection had one open pole. Job was 90 minutes away. Anyone have any thoughts on how often a breaker is bad right out of the box? Not sure if this was a fluke or if I need to check every breaker I buy or always buy 2.

 

[D. Castor]

We used to work with a large chip manufacturer that did trip testing of every new molded case circuit breaker installed in their fabs. They rejected (for all causes) about 3% of all breakers tested.