Thanks Mikesh,
That almost answered my question. I am still wondering... is there acturally an interaction between the breakers for them to trip together, or is there some time/current curve that they are set at, when set up as a system, that meets the criteria to make them trip.... or am I still missing it.
I will look up Cutler Hammer's tech papers on it.
Thanks again.
There is interaction, and it can be very complex. Some interactive items are:
Two sets of contacts resistance in series.
Additional cable is included in the series testing.
As one set of contacts opens it creates additional impedance which severly limits the current seen by the other breaker.
There are many misconceptions about and misapplications of series ratings even though they have existed for almost 20 years.
