> No really because you can run #10 wire from a breaker panel to a location
> where an amp is to avoid voltage drop and then simply use a 20A breaker
> and
> plug on that wire. You don't have to use 30A breaker or plug.
Right, as long as only the wiring is "super-sized" in that application But
to Carl's point, if the 240VAC demand is > 20A, then pricing of 30A material
goes up on a seemingly exponential curve. When I purchased 30A, 4-wire,
twist-lock hardware, I was in a state of sticker shock. I did find a sale
on-line through W.W. Grainger and that lessened the pain.
When I re-wired the shack, I brought in several new 120 VAC branch circuits
feeding single, unshared receptacles and thought I would really "do it
right" by using Leviton secondary-surge-protected, Hospital-Grade, IG
receptacles (another exponential cost multiplier at approx $50 per
receptacle). But using home-run IG receptacles makes little sense for home
wiring where NMC cabling is used. It's certainly more applicable in
commercial and industrial applications where wiring is run in conduit and
the ground wire must be isolated from the ground-potential of the conduit
and associated hardware. In that case, individual THHN wire is typically
pulled in conduit and one can create an insulated ground wire.
In most home wiring, NMC (e.g., Romex) is used and the bare ground wire only
makes contact with the serving main or sub-panel. Arguably, one may want to
keep the bare ground wire insulated right up to the panel's ground block,
but there's probably very little reason for this if the branch is feeding a
dedicated receptacle and only 1-2 feet of ground wire is exposed in the
panel that can possibly make contact with other bare ground wires.
For my new 20A, 120VAC outlets, I tried looking for 12/3 Romex w/o Ground
(i.e., all 3 conductors L-N-G insulated). I could swear this was once
commonly available in a non-metallic sheath but I could not find any at Home
Depot, nor Lowes. 12/3 w/ Ground could have been used with the bare ground
wire abandoned - but that looks like Hell and I'm not sure what the NEC says
about it. My intent was to run an insulated ground wire between the single
20A receptacles right up to the panel ground block.
Paul, W9AC
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