Exam 7: Introduction to Residential Service Entrances

The NEC requires a minimum clearance of __________ feet above residential property and driveways where the voltage to ground does not exceed 300 volts.

Explain why a seal is required anytime a raceway containing electrical conductors is installed from a cold area to a warm area.

A supplemental grounding electrode is a grounding electrode used to "back-up" a metal water pipe grounding electrode.

One set of service entrance conductors is permitted to supply __________ service disconnecting means instead of a single main disconnect.

Direct-buried conductors emerging from the ground must be protected to a point at least __________ feet above finished grade.

Overhead service conductors are permitted to be attached to trees for support.

A(n) __________ is the conductor connected to the neutral point of a system and is intended to carry current under normal conditions.

The enclosure housing a temporary service entrance disconnecting means must be dust-tight.

If a concrete-encased electrode is used, the end of the 4 AWG copper conductor or the end of the re-bar (whichever is used) can be extended from its location in the concrete to an accessible location above the concrete.

A coupling connecting two conduits together for a service mast can be located above the last point of securement to the house.

The overhead service conductors from the last pole to the point connecting them to the service entrance conductors at the building are called __________ conductors.

Copper-coated steel ground rods must be listed and be at least __________ in diameter.

According to NEC Table 250.66, the minimum size copper grounding electrode conductor for a service entrance installed with 4/0 copper conductors is__________.

When a warning ribbon is required to mark the location of buried underground service conductors, it must be placed at least __________ inches above the buried conductors.

_______________ is the term for being connected together to establish electrical continuity and conductivity.

A length of raceway that extends up a utility pole and encloses the service entrance conductors in an underground service is called a(n) _______________.

__________ is a general term used for material, fittings, devices, appliances, lighting fixtures, apparatus, machinery, and other parts used in connection with an electrical installation.

Explain why the NEC and local utility companies require the service entrance disconnecting means, if located inside a house, to be installed as close as possible to where the service conductors enter the house.

The NEC requires a clearance of at least __________ feet above final grade for service conductors where they are connected to the building, above sidewalks and other areas accessible to pedestrians.

If a single grounding electrode that is a rod, pipe, or plate does not have resistance to earth of 25 ohms or less, an additional electrode must be installed.