111 Questions
Which type of battery is increasingly being used in large-scale applications due to its high energy density?
Lithium-ion battery
What gases are liberated by the vented type of lead-acid cell under normal charging conditions?
Hydrogen at the negative plate and oxygen at the positive plate
What is the principal active material in the positive plate of an alkali battery?
Nickelous hydroxide
Which type of cell is commonly used in storage batteries?
Lead-acid
What is the purpose of a thermal barrier in the installation of resistors or reactors?
To provide clearance from combustible materials
What is the minimum clearance required between resistors or reactors and combustible materials in installations over 1000 Volts?
305 mm (12 in.)
What is the recommended practice for the installation of lead-acid batteries for stationary applications?
IEEE 484
According to the NEC, what is the minimum conductor ampacity for a phase converter supplying specific fixed loads, where the conductor ampacity is less than 125 percent of the phase converter nameplate single-phase input full-load amperes?
250 percent of the phase converter nameplate single-phase input full-load amperes
What is the purpose of identifying the manufactured phase conductors in all accessible locations?
To prevent single-phase loads from being supplied from the manufactured phase
If the input and output voltages of a phase converter are different, how should the current be calculated?
By multiplying the current determined by this section by the ratio of output to input voltage
According to the text, what is the rating requirement for the disconnecting means in each ungrounded conductor for each capacitor bank?
It should not be less than 135 percent of the rated current of the capacitor
What is the purpose of connecting capacitors in an induction motor circuit for power factor correction?
To increase the power factor of the motor circuit
According to the text, what should be taken into account when selecting the rating of a motor overload device if a capacitor is connected on the load side of the motor overload relays?
The line current
According to the text, what should be connected to the equipment grounding conductor for capacitor cases?
All capacitor cases
Which of the following is an acceptable use of a phase converter?
To supply a 3-phase distribution equipment such as a panelboard
How should the phase conductor at a central distribution point be identified?
By visible indication
What should be the ampere rating of the disconnecting means for a phase converter?
Less than 115 percent of the rated maximum single-phase input full-load amperes
Where should the disconnecting means for a phase converter be located?
Readily accessible and located in sight from the phase converter
Which of the following is true about capacitors in a motor load circuit?
Capacitors must be connected to the line side of the motor overload protective device.
What is the requirement for enclosing capacitors containing more than 11 L (3 gal) of flammable liquid?
They must be enclosed in vaults or outdoor fenced enclosures.
How quickly should the residual voltage of a capacitor be reduced to 50 volts or less after it is disconnected from the source of supply?
Within 1 minute
What is the ampacity requirement for capacitor circuit conductors?
Not less than 135% of the rated current of the capacitor
According to the text, what is the purpose of the discharge circuit in a capacitor bank?
To drain off the stored charge in the capacitor after the supply circuit has been opened
According to the text, what is the purpose of the interlocks in the switching sequence for series capacitors?
To ensure the proper switching sequence
According to the text, how should capacitor cases be connected in terms of grounding?
They should be connected to the equipment grounding conductor
According to the text, what information should be provided on the permanent nameplate of each capacitor?
Manufacturer's name, rated voltage, frequency, kilovar or amperes, number of phases, and volume of liquid identified as flammable
According to the NEC, what is the maximum allowable voltage drop for conductors sized to prevent a voltage drop exceeding 3 percent of maximum anticipated load?
5 percent
What is the minimum allowable voltage drop for conductors sized to prevent a voltage drop exceeding 3 percent of maximum anticipated load?
2 percent
According to IEEE 1375-2003, what does it provide guidance for?
Overcurrent protection
According to the text, what is the maximum voltage of a battery that does not require overcurrent protection for conductors supplying power for starting, ignition, or control of prime movers?
60 volts dc
According to the NEC, what type of sign should be installed on the disconnecting means enclosure or immediately adjacent to open disconnecting means where the possibility of backfeed exists?
A sign with the word 'DANGER'
According to the text, where should the single-line diagram of the local switching arrangement be provided?
Within sight of each point of connection
According to the text, which part of the NEC covers assemblies of switchgear and industrial control equipment?
Part III
According to the text, what type of conduit is suggested by manufacturers to be used in order to withstand corrosive battery fumes?
Steel conduit with zinc coating
What is the minimum clearance required between a cell container and any wall or structure for battery racks?
25 mm (1 in.)
Which type of battery technology does not require ventilation under normal or abnormal charging conditions?
Sodium-nickel chloride batteries
What is the purpose of the ventilation requirement for battery locations?
To prevent the accumulation of explosive gases
According to the text, what is the purpose of a flame arrester in a vented cell?
To prevent destruction of the cell due to ignition of gases within the cell by an external spark or flame
What is the purpose of a pressure-release vent in a sealed cell?
To prevent excessive accumulation of pressure within the cell during operation
What is the purpose of a ground-fault detector and indicator in battery circuits exceeding 100 volts?
To monitor for ground faults
According to the text, where should gas piping be located in relation to dedicated battery rooms?
Gas piping shall not be permitted in dedicated battery rooms
According to the text, what is the minimum air separation required between bare live conductors and adjacent grounded surfaces for a 14.4 kV system installed outdoors?
305 mm
What is the purpose of isolating switches in electrical equipment?
To completely isolate an item of equipment from all grounded conductors
According to the text, what is the purpose of former Article 490 in the NEC?
To establish product certification standards for equipment rated over 600 volts
What is the impact of the change in Article 490 in the NEC on the availability of disconnecting means for high voltage applications?
Disconnecting means are now available for 1000-volt applications
Which of the following is a requirement for disconnecting battery circuits exceeding 240 volts dc nominal for maintenance?
The disconnecting means must be capable of being locked in the open position.
What is the purpose of remote controls for the disconnecting means of a stationary standby battery?
To activate the disconnecting means
What is the purpose of the marking on the disconnecting means for a battery system?
To indicate the nominal battery voltage
Where should batteries be located and arranged in order to provide sufficient work space for inspection and maintenance?
In clean, dry rooms
According to the text, what type of cells are sometimes used in stationary installations, but require special charging equipment to prevent gas emissions?
Nickel-cadmium cells
According to the text, which type of batteries can generate hydrogen during fault conditions?
Newer-technology batteries
According to the text, what type of batteries does the requirement for listing apply to?
All battery types except lead-acid
Which type of battery generally requires special charging equipment to prevent gas emissions?
Nickel-cadmium
What type of batteries does the requirement for listing in Article 480 not apply to?
Lead-acid
Which type of battery is commonly used in storage batteries?
Lead-acid
Which of the following is a requirement for disconnecting battery circuits exceeding 240 volts dc nominal for maintenance?
Fuses and fuseholders designed for future replacement without de-energizing the fuseholder shall be used.
What is the purpose of the ventilation requirement for battery locations?
To prevent hydrogen accumulation and ensure safe battery operation.
According to the text, what is the maximum voltage of a battery that does not require overcurrent protection for conductors supplying power for starting, ignition, or control of prime movers?
240 volts
Which NFPA standard provides guidance for the classification of flammable liquids, gases, or vapors and of hazardous (classified) locations for electrical installations in chemical process areas?
NFPA 497
Which NFPA standard provides guidance for the classification of locations for drycleaning facilities?
NFPA 32
Which NFPA standard provides guidance for the classification of locations for spray application using flammable or combustible materials?
NFPA 33
Which of the following is a requirement for doors that provide access to high-voltage energized parts in switchgear or control assemblies?
They must be locked
What is the purpose of installing permanent signs on panels or doors that provide access to live parts over 1000 volts?
To warn of high voltage
Where should control equipment, relays, motors, and the like be installed in relation to high-voltage parts or high-voltage wiring?
In a separate compartment
What is the purpose of interlocks for interrupter switches equipped with stored energy mechanisms?
To prevent access to the switch compartment
According to the text, what is the purpose of the ground bus in switchgear used as service equipment?
To facilitate the attachment of safety grounds for personnel protection
According to the text, what is the purpose of the mechanical interlocks in circuit breakers equipped with stored energy mechanisms?
To prevent the complete withdrawal of the circuit breaker from the housing
According to the text, what is the requirement for locking circuit breakers in the open position?
The locking provision must be lockable open
According to the text, what is the purpose of the single-line diagram of the switchgear?
To identify interlocks and isolation means
According to the text, which hazardous locations are covered by NFPA 495, Explosive Materials Code?
Class I, Division 1 or Class I, Division 2
According to the text, which hazardous locations are not covered by NFPA 495, Explosive Materials Code?
Zone 0, Zone 1, or Zone 2
According to the text, what type of equipment is not covered by NFPA 495, Explosive Materials Code?
Non-electrical equipment
According to the text, what is the purpose of area classification drawings and associated documentation?
To document hazardous (classified) locations
Which type of locations are covered in Articles 500 through 516 of the NEC?
Locations with classified materials
What is the flash point temperature for a flammable liquid according to the text?
Below 100°F
What is the purpose of the bonding requirement for non-current-carrying metal parts of a boiler according to the text?
To prevent electrical shock
What is the purpose of the pressure and temperature limit control in a boiler according to the text?
To shut off the current flow through the heating elements
According to the text, what is the requirement for enclosing energized switching and control parts in mobile and portable equipment?
They should be enclosed in grounded metal cabinets or enclosures.
According to the text, what is the purpose of disconnecting means for mobile and portable high-voltage equipment?
To disconnect all ungrounded conductors.
According to the text, what is the requirement for collector ring assemblies on revolving-type machines?
They should be guarded to prevent accidental contact with energized parts.
According to the text, what is the requirement for power cable connections to mobile machines?
They should be enclosed in metallic enclosures with grounding connections.
Which standard provides guidance for the classification of hazardous (classified) locations for electrical installations in chemical process areas?
NFPA 820
Which standard provides information on protection against static electricity and lightning hazards in hazardous (classified) locations?
NFPA 77
Which standard provides information on electrical systems for hazardous (classified) locations on offshore oil- and gas-producing platforms, drilling rigs, and workover rigs?
ANSI/API RP 14F
Which NFPA standard provides guidance for the classification of locations for spray application using flammable or combustible materials?
NFPA 51
Where should the single-line diagram of the local switching arrangement be provided?
NFPA 409
What is the purpose of the interlocks in the switching sequence for series capacitors?
To prevent short circuits
What is the principal active material in the positive plate of an alkali battery?
Lithium
What is the purpose of the area classification drawings and associated documentation?
To ensure proper installation of electrical equipment in each classified area
Which standards provide information on electrical resistance trace heating for hazardous locations?
IEC/IEEE 60079-30-2
What type of documentation consists of area classification drawings?
Hazardous area documentation
Which NFPA standard provides guidance for the classification of flammable liquids, gases, or vapors and of hazardous (classified) locations for electrical installations in chemical process areas?
NFPA 497
Which organizations can be used to classify locations according to NFPA standards?
Both NFPA and API
What factors must be considered when classifying an area?
All of the above
What happens if different types of flammable materials exist in a process or location?
The area is classified as both a Class I and a Class II location
Is equipment suitable for use in a Class I location also suitable for use in a Class II location?
No, equipment suitable for use in a Class I location is not suitable for use in a Class II location
Which of the following factors is NOT considered in determining the classification and extent of a location?
The record of the industry or business with respect to explosions or fires
Which of the following is a factor in determining the need for a Class II classified location?
All of the above
Which of the following statements about Class II, Division 1 locations is correct?
They are locations where combustible dust is present in the air under abnormal operating conditions
Which of the following statements about Group E dusts is correct?
They are particularly hazardous due to extreme precaution necessary to avoid ignition and explosion
Which group of chemicals in NFPA 497 is characterized by having a maximum experimental safe gap (MESG) value less than or equal to 0.45 mm or a minimum igniting current ratio (MIC ratio) less than or equal to 0.40?
Group B
Which chemical is mentioned as a typical Class I, Group B material in the text?
Hydrogen
Which NFPA standard provides guidance for the classification of combustible dusts and hazardous (classified) locations for electrical installations in chemical process areas?
NFPA 499
Which of the following locations is typically classified as a Class I, Division 1 location?
Interiors of refrigerators and freezers in which volatile flammable materials are stored
Which of the following is a requirement for Class I, Division 2 locations?
Volatile flammable gases, flammable liquid-produced vapors, or combustible liquid-produced vapors are normally prevented by positive mechanical ventilation
Which of the following is a requirement for the installation of instrumentation or other electrical equipment in Class I, Division 1 locations?
It should be essential to the process and other locations are not feasible
Which of the following locations might become hazardous through failure or abnormal operation of the ventilating equipment?
Locations where ignitible concentrations of flammable gases are normally prevented by positive mechanical ventilation
Which locations shall be classified as Class III, Division 1?
Locations where nonmetal combustible fibers/flyings are in the air under normal operating conditions
Which materials can be classified as ignitible fibers/flyings?
All of the above
Which locations shall be classified as Class II, Division 1, Group E?
Locations where metal combustible fibers/flyings are present
Which locations shall be classified as Class III, Division 2?
Locations where nonmetal combustible fibers/flyings might be present due to abnormal operations
This quiz tests your knowledge of mechanical stresses in air-core reactors and the guidelines for spacing, bracing, and fastening supporting insulators. It also covers the rules regarding reconditioned equipment and resistors. Are you ready to test your knowledge of 1000 volts or less electrical systems?
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
