Devices and circuits Chapter 9
Phases to phases voltage should not be more than ____________ percent from an average of all phases to phase readings.
1
In most commercial industrial applications, an _______ amp branch circuit is the most commonly installed general purpose branch circuit.
20
Most commercial and industrial lighting circuits operate at ________ V.
277
Per the NEC, voltage drop on the feeder should never exceed ________ %.
3
A three pole, single throw switch is abbreviated as ______.
3PST
Any piece of electrical equipment rated 480 V and below must have a minimum resistance of __________ megaohms when measured with a Megohmmeter.
5
The total combine voltage drop of the feeder on a branch circuit should be no greater than ________%.
5
Tap conductors that run from an outlet box in an overhead raceway to a luminaire with a C or MC cable must be at least 18 inches but not more than _______ foot in length.
6
In large industrial facilities, underground feeders usually operate at voltages of ________ volts and higher.
600
An _______ Circuit breaker has mechanisms for time and current that can be manually adjusted
Adynleble
An ______ Circuit is a part of an electrical wiring system between the final set of circuit breakers or fuses and the fixtures and receptacles.
Branch
An _______ test is the momentary energizing of a motor before it is coupled to the load to observe the direction of rotation.
Bump
________ frequency is the very high frequency from about 1kHz to about 20kHz of the short voltage pulses of varying length that simulate a lower frequency
Carrier
An ________ Motor is a three phase electric motor that is capable of operating on more than one voltage system.
Dual voltage
Selection of overcurrent devices is decided by the ________ as part of the project design.
Engineering firm
An _______ receptacle has a spring-loaded cover on the receptacle housing to protect the receptacle when not in use and is used with water tight plugs that are rotated and locked in place before power can be turned onto the equipment.
Enterproof
A Megohmmeter applies a low voltage to circuits under test?
F
A metal halide lamp produces less lumens per watt than a mercury vapor lamp.
F
Ambient air temperature does not affect overload relay operation?
F
An individual branch circuit is a branch circuit that supplies energy to one or more outlets?
F
Grounded and ungrounded conductors can open simultaneously?
F
No more than one four-way switch can be used in the same circuit?
F
Some receptacles can except attachment plugs of different voltages or current ratings in those for which they are specifically intended.
F
The most common switch used in commercial and industrial installations is single pole, single throw switch?
F
The voltage rating of a device must always be less than the nominal system voltage?
F
Three way switches must always be used in sets of three?
F
Three-phase motors are less efficient energy conversion than single phase motors?
F
An ________ lamp is a low pressure discharge lamp in which ionization of mercury vapor transforms ultraviolet energy generated by the discharge into light.
Fluorescent
After the battery is installed, the emergency lighting unit must be tested to verify that the emergency lights can ________.
Function during a power loss
A ________ is an electrical overcurrent protection device with a fusible portion that is heated and broken by the passage of excessive current.
Fuse
________ receptacles are required by the NEC to be installed in areas such as bathrooms, kitchens, outdoor locations, garages, and rooftops
GFCI
An ________ is a short circuit between conductors and grounded parts.
Ground fault
An _________ receptacle is identified by a test and reset button on the face of the receptacle.
Ground fault circuit interrupter
________ are intended for the protection of personal and rapidly the energize is a circuit when the current ground exceeds 4mA to 6mA.
Ground fault circuit interrupters
GFCI receptacles trip when the difference between ungrounded and ________ conductor current exceeds a difference of 4 mA to 6 mA.
Grounded
An _____ lamp produces light from an arc tube.
HID
Breakers installed for switching high intensity discharge lighting must be marked as _________ by the manufacture
HID
A _______ lamp produces light when current flows through sodium vapor under high pressure and high temperature.
High pressure sodium
An ________ ground receptacle is a receptacle in which the grounding terminal is isolated from the device yolk or strap.
Isolated
An ________ receptacle is used for protection for computers and other sensitive electronics equipment from electromagnetic interference and electrical noise caused by harmonics and undesirable current flow on the EGC.
Isolated ground
In a _______ bend, the conductor does not enter or leave the enclosure through the wall opposite it's terminals.
L
Because motors vibrate as they operate, ________ is often used for at least 6 foot or less of raceway prior to entering the motor.
LFMC
________ current is electric current flows through insulators on a conductor.
Leakage
An ________ lamp is commonly used for street, highway, parking lot, and flood light applications.
Low pressure sodium
The amount a light and a lamp produces is expressed in ________.
Lumens (Lm)
A ______ is a complete lighting unit including the components that distribute light, position and protect the lamps, and provide connection to the power supply.
Luminarie
An _______ is an electrical operated switch that includes motor overload protection.
Magnetic motor starter
An ______ lamp is an HID lamp that produces light by an Electrical discharge through mercury vapor.
Mercury vapor
The four basic types of HID lamps are used in commercial and industrial installations include low pressure sodium, mercury vapor, high pressure sodium, and __________.
Metal handle
A _______ is a device or group of devices used to manually or automatically control electric power to a motor
Motor controller
An _______ branch circuit consists of a minimum of two underground conductors with a potential difference between them, and a grounding conductor with a potential difference between it and the underground conductors
Multi-wire
An _______ is a small magnitude overcurrent that, overtime, can active a overcurrent protection device.
Overload
A low pressure sodium lamp has a U-shaped arc tube?
T
A utility lineman rather than an installer typically performs overhead feeder installation?
T
An adjustable circuit breaker has mechanisms for timing current that can be manually adjusted
T
An insulation resistant spot test must be performed at regular intervals?
T
Bonding jumpers are not required where there is direct metal to metal contact between a receptacle and a device box or where the receptacle yolk has a spring type grounding strap?
T
Burning jumpers are not required for cover-mounted receptacles and ground and metal boxes.
T
Device conducts, but does not use, electrical energy?
T
Devices are used to carry electrical energy to utilization equipment?
T
For motors that are already in service, the information provided on the motor nameplate is often the only information available for reference purposes?
T
Green terminal screws are used for terminating grounding and bonding conductors?
T
Hospital grade receptacles can be installed in institutional and industrial locations?
T
Most motor nameplates include the motors wiring diagram?
T
Only underground conductors can be opened by switches?
T
Overcurrent protection devices or 800 A or less, which do not correspond to a standard size Device listed in the NEC are rounded down to the next standard device?
T
Tap conductors that run from one outlet box in the overhead raceway to the luminaire must be at least 1 foot from the luminaire?
T
The more lumens produced by a light source per wire of power used, the more efficient the light source is in producing light?
T
The most common method used to identify conductors in an insulation color coding system?
T
The unit of measure of illumination is the lumen?
T
When installing a dual voltage motor, the higher voltage is preferred when a choice between voltages is available?
T
An _______ fluorescent lamp is inch and a half in diameter and 48 inches long.
T-12
A ______ is a connection from one conductor to another to obtain power from the conductor to which the connection occurs.
Tap
An _________ is a requirement that must be met to allow conductors to be run without short circuit and ground fault protection at the point where they receive their power supply.
Tap rule
_______ Motors are commonly used in industrial applications such as freight elevators, mixing equipment, conveying equipment, and material processing.
Three phase
An ________ is a permanent barrier that prevents connection between adjacent conductors through arcing or indvertent touching of conductors.
Voltage barrier
_________ is the effect that occurs when the light falls on a surface.
illumination