Chapter 16 EO test

The recommended approach to provide adequate lighting in a residential garage is to install one ____-watt lamp on the ceiling above each side of an automobile.

100

The minimum depth for a 120-volt, 15-ampere, GFCI-protected circuit to an outdoor pole light run under a paved driveway is ____.

12 inches

Permanent overhead conductor spans are permitted to be supported by live or dead vegetation, such as trees.

False

Explain why a post lamp cannot be grounded only with a local ground rod, but must have a separate grounding equipment conductor going back to the residential service.

NEC 250.4(A)(5) states the earth shall not be considered as an effective ground-fault current path.

Explain why, in colder parts of the country, incandescent fixtures are more suitable than fluorescent for unheated spaces like garages.

Standard fluorescent lamps installed in a cold garage would be difficult if not impossible to start.

Direct-burial cable is normally required to have a minimum of 24 inches of earth cover. Explain the conditions under which the minimum depth can be reduced to 12 inches for residential occupancies.

The minimum depth is reduced to from 24 in. to 12 in. for residential installations when the branch circuit is not over 120 volts, is GFCI protected, and the overcurrent protection is not over 20 amperes.

If you are experiencing too much lamp burnout in your garage door opener, the culprit is probably vibration.

True

What type of cable is permitted to be used for direct burial applications?

Type UF

The recommended approach to provide adequate lighting in a residential garage is to install one ____-watt lamp on the ceiling above each side of an automobile.

are

Overhead conductors ____ permitted to be supported by trees.

are not

Metallic conduit buried underground must be protected against ____.

corrosion

The last sentence of 250.4(A)(5) states that "The earth shall not be considered as an effective ____________________."

ground fault current path

Conductors suitable for use in ____________________ locations will have the letter "W" in their type designation.

wet

Minimum cover requirements for direct-buried cables and raceways under a variety of conditions are given in Table ____________________.

300.5

Type UF "underground feeder" cable ____ permitted to be used to supply service entrances.

is not

When outdoor receptacles are installed where a cord will be plugged in permanently, such as for decorative lighting, the box cover ____ provide weatherproof integrity when the cord is plugged in.

must

According to NEC 210.52(G)(1), in each attached garage and in each detached garage with electric power, at least ____ receptacle outlet shall be installed in each vehicle bay and not more than 5½ ft (1.7 m) above the floor.

one

Explain the rationale for installing supplemental overcurrent protection, such as a "box cover unit" with a switch and fuse combination, to protect an appliance or utilization equipment such as a garage door opener.

The objective is to have a lower ampere rating fuse than the 15- or 20-ampere branch-circuit breaker. Should a short circuit occur within the overhead door operator, the lower ampere rated fuse will open faster than the 15- or 20-ampere branch-circuit breaker. This takes the overhead door operator off the branch circuit.

Article ____________________ covers low-voltage lighting systems operating at not greater than 30 volts ac or 60 volts dc.

411

To provide shock protection, low-voltage wiring systems are required by Article 411 to be ____.

supplioed through isolating transformers