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