Wire bundle in overhead open attic garage.

[Papa-Gus]

I'm in the process of upgrading electrical wiring in a forty year old single resident home located in Southern California. NEC requires, in layman terms, that main distribution panel wire bundle penetrating garage firewall to be fastened to a horizontal support (e.g. wooden planks), secured to the rafters; as was done by the builder. Is there anything, code related, preventing me from splitting up the wire bundle into two separate runs; each fastened to respective horizontal supports coming through separate firewall penetrations? I need to reroute some general purpose and appliance wiring to a disconnect sub-panel and doing what I propose will save me much time and expense.

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[pushkins]

No, there is nothing that says you cannot do that as long as all fire blocking is still maintained at each penetration.

[Papa-Gus]

Greatly appreciated pushkins;

Intumescent foam around all firewall penetrations. Sealed attic, radiation barrier and R -∞ fiberglass batt insulation comes after the wiring and plumbing. Nice forum; thanks!!!

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[HayZee518]

if you are going to run a feeder to a sub-panel, you'll need a four wire cable, i.e. 6-4 for a 60 amp sub panel.
at the sub panel you don't use the bonding screw for the neutral bus.
you'll need an auxillary ground bus which fastens to the chassis of the sub-panel.
a sub lug panel is usually used for a sub-panel. [ main lugs, no main breaker]
white to neutral, bare or green to aux bus, red/black to main lugs.
at your regular panel, both the white and green go on the main neutral bus.

[Papa-Gus]

Thank you for your input. This confirms my installation meets code regarding wire size. The sub panel is actually a generator disconnect/sub panel with bolt secured back fed breakers.

HayZee518, my questions are:

Is an auxillary ground necessary for a generator disconnect/sub panel?

If yes, should the generator disconnect/sub panel be tied to the auxillary ground with present ground connection to the load center and cold water pipe removed?


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[HayZee518]

any box with breakers to protect downstream circuits is called a sub panel. hencetoforth, if there is no cold water pipe in which to use as a ground, then a 5/8" diameter, 8ft long copper clad ground rod should be driven full length with a minimum of #6 stranded copper wire should be used and be tied to an auxilary ground bus within the panel. the neutral bus shall NOT be bonded [tied] to chassis ground. whatever your load is, wire size should compensate for it. i.e. 10 ga for 30 amp, 12 ga for 20 amp, 8ga for 40 amp, 6 for 60 amp - and all contained within a four wire jacket. 10/4, 6/4, 12/4 etc.