15 Minute Tech Talk - Series Ratings

[@j.w.2093]

In the graphics you have shown, where motor fault current contribution effects adjacent circuit breakers' fault current, I don't see how 240.86C is written properly to address this concern. Instead it seems to be written to address only a series rated pair at a given motor, or a motors connected in the middle of a series rated pair.

[@j.w.2093]

How does an arc energy reduction maintenance switch effect downstream series rated breakers?

[@j.w.2093]

Since the new rule 240.87 may apply when someone is replacing a breaker in a switchboard, what happens when someone is installing a downstream breaker over 1200 A and that breaker was originally configured to be series rated and now you have to have a fast overcurrent setting for arc energy reduction? It would present a greater hazard to install such a thing and forcing one to replace the entire switchboard instead of just 1 breaker is a lot.

[@j.w.2093]

Another reason to need a PE to be involved in series rating per 240.86A: Modifications to facilities where there will be different circuit breaker manufacturers.

[@educationpower1823]

Cannot hear what you say volume way to low

[@TDUNPLUGGED]

Education Power Volume was off in the very first few seconds of the video. I should just edit the beginning out but left it as is. Thanks for the feedback.