Power Distribution - Low current breakers or fuses?

[DonRotolo]

Originally Posted by diviney

This statement appears in <R45>: "In addition to the required branch power circuit breakers, smaller value fuses or breakers
may be incorporated into custom circuits for additional protection".

Yes, and that's what R82-84 implies: So long as you start with a KOP breaker, you feed it to your custom circuit (which can have a fuse holder, holding a small fuse). If the 2008 rules were in force, I'd get a bunch of the Keystone fuse clips and build a distributor (a custom circuit in its own right) for my custom circuits, or buy one as COTS - I'd ask for an interpretation of R45 for that case, since it is pretty clear in what it says.

On a related subject: When proper fusing is not an option, the next step is an FMEA analysis, and take actions to address the modes that could impact current draw. The goal is then to limit the damage that overcurrent could cause. In such cases I might employ teflon insulated wire to handle the heat, manage the heat (forced cooling for the wire), protect the wire from damage, or something like that. In some cases, protecting the wiring is sufficient as the circuit is intrinsically current-limited.