Wiring & Installation Techniques Flashcards

When installing a ceiling fan, the electrical box must be rated for:

Answer: Fan support with the weight listed on the box

NEC 314.27(C) requires ceiling fan outlet boxes to be listed specifically for fan support, rated for the fan's weight.

The color code for a 3-phase, 480-volt system's high-leg (wild leg) conductor is:

Answer: Orange

NEC 230.56 requires the high-leg (wild leg) of a 4-wire delta system to be identified with orange color.

When using staples to secure NM cable, what is the maximum interval between staples in a vertical run?

Answer: 4.5 feet

NEC 334.30 requires NM cable to be supported and secured at intervals not exceeding 4.5 feet (54 inches) along vertical runs.

In a 3-wire, 240/120V single-phase system, if one hot leg fails, what happens to 120V loads on the remaining leg?

Answer: They operate normally at 120V

In a 3-wire system, each 120V load is connected between one hot leg and neutral, so loads on the intact leg continue to operate normally.

What is the minimum cover required for a raceway installed under a concrete slab with no vehicular traffic?

Answer: 0 inches — no cover needed

NEC Table 300.5 permits raceways installed under a concrete slab to have zero additional cover since the slab itself provides protection.

When terminating conductors in a panelboard, which tool is used to verify proper torque on terminal screws?

Answer: Calibrated torque screwdriver or wrench

Torque specifications on terminals must be met using a calibrated torque screwdriver or wrench to ensure proper electrical connections.

Which wiring method is required when installing conductors in a hazardous (classified) location Class I, Division 1?

Answer: Rigid metal conduit (RMC) with threaded fittings

Class I, Division 1 hazardous locations require threaded rigid metal conduit or threaded steel IMC to contain any ignition of flammable gases.