---My point is that if the switchboard is only rated for 3-cycles, should they prohibit the time delay more than 3-cycles for a bloted fualt?
First, be sure you read my previous disclaimer:-? I'm a bit out out on my area - I do my danmedest to stay out of the design business. I'm a fixer. With that in mind:
I'm thinking this stuff shows up on the coordination study. For this size project, the study is pretty through. The first sheet shows the cable damage curves, transformer damage points, inrush currents, bolted fault currents, ground fault currents ... And the over current protection device curves have to be inside of all of the damage curves. i don't do the studies, but i look at them and do a lot of verification they look to be truth.
Now I'm thinking that if the switchboard damage toa fault is questionable, then that damage point has to be on the coordination sheet and the OCP set inside of that damage point.
I don't think anybody is going to give you a receipe for this. You're the one that is doing the coordination/fault current study and is making sure the OCP is coordinated with the equipment damage curves. I don't see a switchboard damage point as any different than a transformer damage point or a cable damage curve.
What do you think?
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