Electrical Systems & Wiring Installation Flashcards

When installing recessed lighting in an insulated ceiling, which fixture type must be used?

Answer: Type IC (Insulation Contact) rated fixtures

IC-rated fixtures are designed to be in direct contact with insulation without creating a fire hazard.

What is the maximum allowable ampacity for a 10 AWG THHN copper conductor at 75°C?

Answer: 30 amps

10 AWG THHN copper has an allowable ampacity of 30 amps at 75°C per NEC Table 310.15(B)(16).

In a commercial installation, what color is typically used for the high-leg conductor in a 3-phase 4-wire delta system?

Answer: Orange

The high-leg (wild-leg) conductor in a 3-phase delta system must be identified with orange color per NEC 230.56.

What is the correct method for securing MC (Metal Clad) cable within 12 inches of an outlet box?

Answer: Use an approved cable staple or strap alongside the cable

MC cable must be secured within 12 inches of every box using listed staples or straps that do not damage the cable.

Which of the following is a required step when connecting aluminum conductors to terminals rated only for copper?

Answer: Apply antioxidant compound and use a CO/ALR rated device

Aluminum conductors require antioxidant compound and CO/ALR rated devices when terminating to prevent oxidation and loosening.

What is the NEC rule regarding the use of extension cords as a permanent wiring method?

Answer: Prohibited — extension cords cannot serve as permanent wiring

NEC 400.12 explicitly prohibits the use of flexible cords and cables as a substitute for fixed wiring.

When running wiring through fire-rated walls or floors, what is required at penetration points?

Answer: Approved firestop systems or materials filling the annular space

All penetrations through fire-rated assemblies must be sealed with listed firestop systems to maintain the fire rating.