DIY

Subpanel feeder sizing comes from the calculated load and the overcurrent device protecting it, not from adding up the ratings of the breakers it will supply.

A branch-circuit load calculation uses defined methods and demand factors rather than a simple sum of nameplate ratings, because not everything runs at once.

Where GFCI protection is required is determined by the location of the receptacle or equipment, and the list has expanded steadily across code editions.

Circuit directory labelling must identify each circuit clearly and specifically, because vague entries fail the person trying to kill the right circuit in a hurry.

Panel working clearance is a code requirement about the space in front of and around a panel, and storing things there makes the installation non-compliant.

Cable damage from fishing happens during the pull, where sharp edges, excessive tension and tight bends strip sheath in places nobody will ever inspect.

Nail plate protection is required whenever cable sits closer to the framing face than the specified distance, and eyeballing that distance is how cables get pierced.

Notching and boring studs for cable is governed by building code limits on how much material may be removed, and boring near the centre is structurally kinder.

Attic cable routing decisions determine whether a run gets stepped on, buried in insulation or chewed, and the right choice costs nothing at installation time.

Exposed NM cable protection rules depend on whether the cable is subject to physical damage, which is a judgement about the space rather than about the cable.