Thanks
@automatikdonn and good question - the reason for that is simply because we're more likely to lose a contactor coil (both throws of a single contactor) than we are to lose
half of a contactor (one throw only). In this failure case, we lose half of our split phase on the 'Inverter Load Service Panel', and - assuming we are running < 32A single-pole breakers, our 120V loads will either a) be disconnected completely, or b) remain operational, but still maintain fault capacity to trip their OCPD.
I've made an additional update that simplifies this a bit by chaining the contactors together through the voltage protection devices. This makes the system all-or-nothing (ideally), such that
both contactors are either fully engaged or fully disengaged (effectively acting like a 4PDT, with each pole carrying 40A).
I also added in where I'd recommend putting the scope leads when simulating a neutral failure (and on-grid to off-grid) transition. Ultimately the goal is to measure what the voltage spike/dip would be for 120V devices in the 'Inverter Load Service Panel'.
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