Chapter 28 EO test

Identified handle ties are permitted to disconnect all conductors of a service as long as it takes no more than ____________________ operations of the hand to shut everything off.

6

Nontime-delay fuses are not the best choice for motor circuits because of the high starting inrush current of motors.

True

A(n) ____ is a condition when a "hot" or ungrounded conductor comes in contact with a grounded surface

ground fault

Plug fuses shall have a(n) ____ configuration somewhere on the fuse when rated at 15 amperes or less.

hexagonal

Current-limiting overcurrent devices will limit the amount of ____________________ by opening so fast that the full value of fault-current will not be reached

let-through current

A short circuit in a branch circuit that also causes the main breaker to trip, resulting in a total power outage, is an example of ____________________ coordination.

nonselective

A(n) ____ is a condition where the current flowing in a circuit is more than the current and/or connected equipment is designed to handle.

overload

Overcurrent protection for residential services, branch circuits, and feeders is provided by circuit breakers or fuses. These are the "____" of an electrical circuit.

safety valves

The unique characteristic of a(n) ____________________ combination is that the upstream circuit breaker has a high interrupting rating and the downstream circuit breakers have a low interrupting rating.

series-rated

Cartridge fuses are available in Class H and Class R types.

True

A(n) ____ is a condition when two or more normally insulated conductors come into contact with one another, resulting in a current flow that bypasses the connected load.

short circuit

The ____________________ rating of a panelboard is derived by testing the panel as an assembly with breakers and/ or fuses installed in the panel.

short-circuit

The term ____________________ refers to how long it will take a fuse or circuit breaker to open under different current values.

time-current

With a ____ fuse, one fuse element opens quickly when a short circuit, heavy overload, or ground fault occurs, and the other element in series with the first element opens slowly on overload conditions.

time-delay, dual element

The maximum ampere rating of a Type S fuse is ____.

30

Circuit breakers with an interrupting rating other than ____ shall have this rating marked on the breaker.

5000 amperes

____ fuses are special-purpose fuses that are found in original equipment, or in commercial and industrial panelboards, multimetering equipment, and motor controllers.

Class CC, Class G, and Class T

Fuses are an economical form of overcurrent protection, albeit unreliable.

False

____________________ loading of a circuit is when the current flowing is within the capability of the circuit and/or the connected equipment.

Normal

All new plug fuse installations shall be ____________________ fuses.

Type S