Chapter 27 EO test

Using an electric rate of $0.07824 per kWh, calculate the cost of running ten 100W lamps for six hours.

. Cost = watts × hours used × cost per kWh/1000 10 lamps at 100W = 1,000W 1,000 x 6 hours x $0.07824 divided by 1000 =$0.46944 46.9¢

If extra support is not to be provided, the mast service conduit must be not smaller than trade size ____ (metric designator 53) rigid metal conduit.

1-1/2

For a one-family residence, the minimum size main service disconnecting means is ____ three-wire.

100-ampere

NEC ____________________ provides rules for working space around electrical equipment.

110.26

NEC 300.4(F) states that if ____ AWG or larger ungrounded circuit conductors enter a cabinet, box enclosure or raceway, an insulating bushing or equivalent must be used.

4

A "zone" equal to the width and depth of the electrical equipment, from the floor to a height of ____ above the equipment or to the structural ceiling, whichever is lower, is required to be dedicated to the electrical installation.

6

Ground rods must be at least ____ ft. in length.

8

Describe a service drop.

A service drop comprises the overhead conductors between the utility distribution system and the service point.

What are service lateral conductors?

If installed by the electric utility, the conductors installed between the pad-mounted transformer and the meter are called service lateral conductors.

A 4 AWG bare copper conductor at least 20 ft (6.0 m) long installed identically to the steel reinforcing rod is also permitted as a concrete-encased grounding electrode. This is often referred to as a(n) ____________________ ground.

UFER

A main service disconnect shall not be installed in a ____.

bathroom

Ground clamps used for bonding and grounding must be ____.

listed for the purpose

For typical residential wiring, the grounding electrode conductor is run between the ____________________ neutral/ground terminal bar and the grounding electrode system.

main service panel

Bonding at service-entrance equipment is very important because service-entrance conductors do not have ____________________ at their line side, other than the electric utility company's primary transformer fuses.

overcorrect protection

Only power service-drop conductors or ____________________ service conductors are permitted to be attached to and supported by the service mast.

overhead

Where exposed to the weather, raceways enclosing service-entrance conductors shall be ____ and arranged to drain.

rain tight

It is extremely important that a disconnect or panelboard used as service equipment be marked "____________________."

suitable for use as service equipment

When using a metal water pipe as a grounding electrode, a(n) ____________________ is required.

supplemental electrode

The watt-hour meter measures and records both wattage and ____________________.

time

When nonmetallic-sheathed cable is used, a panelboard must have a(n) ____________________ for attaching the equipment grounding conductors,

terminal bar