CIW Chapter 8 Flashcards
A grounding ___ is a metal component that contacts the earth and has a conductor connect to it.
electrode
Panelboards in commercial and industrial facilities are often 480/277 V panel boards or ___ panel boards.
208/120 V
Mechanical grounding connectors are typically composed of high- ___ alloy.
copper
When installing service disconnects, they must be grouped together with no more than ___ in one location.
six
A(n) ___ is an electrical conductor used to connect non-current carrying metal parts of equipment or enclosures to the system grounding conductor or grounding electrode.
equipment grounding conductor (EGC)
Examples of separately derived systems include ___, solar photovoltaic systems, generators, and transformers.
batteries
A(n) ___ is a device located over and around contacts to cool and extinguish an electrical arc when contacts open under load.
arc chute
___ transformers isolate the power circuit from the control circuit, providing additional safety for the circuit operator.
Control
If an EGC is larger than 6 AWG, ___-colored insulation is used
black
A ___ point is the point at which utility conductors are connected to a facility wiring system.
service
Transformer hum is the sound produced by the vibrations of the metal ___ of a transformer core.
laminations
Typically, motors that operate above 100 V are expected to operate at 90% to ___% of their voltage rating.
110
A ___ is an electrical device that switches and transforms incoming distribution voltages down to plant-distribution voltage levels.
unit substation
A metering ___ is a group of electrical service meters in a facility.
system
A(n) ___ washer is a round washer that is split, slightly bent, and installed between a nut and the surface of the workpiece.
lock
A(n) ___ is a connection for electrical service equipment that ties together the equipment grounding conductor (EGC) and the grounding electrode conductor (GEC).
main bonding jumper (MBJ)
Electrical insulation on most conductors used in systems rated at 480 V and below is rated for ___ V maximum.
600
The AC energy transfer in a transformer is made magnetically through the ___.
iron core
Bonding methods are used to protect personnel and equipment from ___.
ground-fault conditions
As a distribution system operates, the ___ can vary due to loads cycling on and off.
voltage
The NEC does not permit the use of conductors smaller than ___ AWG for copper for wiring in applications up to 2000 V.
14
When electrical equipment is stored, temporary space heaters can be used to maintain a temperature that is ___.
10 degrees above ambient temperature
A typical ___ combines individual control units into standard modular structures, which are joined together for convenience.
motor control center
___ of transformers can be provided by covering, shielding, fencing, enclosing, or otherwise prohibiting approach or contact by persons or objects.
Physical protection
A typical ___ ignites powdered copper-oxide and aluminum to produce a heat reaction.
exothermic welding process
