Wiring & Installation Techniques Flashcards

When installing a subpanel in a detached garage, the grounding electrode conductor must be connected to:

Answer: A grounding electrode at the detached structure

NEC 250.32 requires a separate grounding electrode system at each detached structure supplied by a feeder or branch circuit.

What is the maximum number of quarter-bends (90° bends) allowed in a single conduit run between pull points?

Answer: 4 bends (360° total)

NEC 358.26 (and other conduit articles) limit the total bends between pull points to 360 degrees (equivalent to four 90° bends) to allow conductor pulling.

When splicing conductors in a junction box, what is required for all splices?

Answer: Wire nuts approved for the wire gauge

NEC 110.14 requires splices to be made with listed devices (such as wire nuts rated for the conductor sizes) and must be accessible.

A 240V, 30-amp dryer circuit requires conductors sized at minimum:

Answer: 10 AWG

A 30-amp circuit requires 10 AWG copper conductors, as 12 AWG is only rated for 20 amps.

When installing recessed lighting in an insulated ceiling, the fixture must be:

Answer: Rated IC (Insulation Contact)

NEC 410.116 requires recessed fixtures installed where insulation will contact them to be marked 'IC' (Insulation Contact) rated.

The purpose of a 'pigtail' connection at a device is to:

Answer: Ensure the circuit continues if the device fails or is removed

Pigtailing ensures the circuit remains complete even if the device is removed, unlike a pass-through connection that breaks the circuit.

When sizing a conduit for a pull, the largest conductor's diameter is used to calculate the:

Answer: Minimum conduit diameter and total fill percentage

Both the largest single conductor diameter (for jam ratio) and total cross-sectional area fill percentage must be checked when sizing conduit.