Approximately how much voltage does the ballast for a high-pressure sodium bulb supply to start the arc in the lamp?
2,500 volts
On a circuit that is grounded, does the worker become part of a series circuit or does he become a parallel circuit to Earth?
He becomes a parallel circuit. Both the worker and the ground will carry current to ground.
Although it takes a certain amount of voltage to push electric current through the human body to cause electrical shock, there are three things that cause damage to the body. List them.
1. Current
2. Exposure Time
3. The path the current takes through the body.
Working on a bracket grounded conductor is similar to working on a neutral conductor; the voltage may be low but there could be a substantial ________ ________.
Current Flow
What is the purpose of the semi conducting shielding on underground cables?
Helps spread the electric field uniformly.
When removing semi-conducting material why is it critical to make an even square cut?
Jagged edges become high stress areas. The electric field concentrates at the end of a jagged cut.
What is the primary purpose of the cable jacket or sheath?
C) Provide mechanical protection
When laying duct in a trench between two manholes, where should you start?
D) Start at the midpoint where duct spacing is standard
By law, who is responsible for the pre-trip inspection of a fleet vehicle?
D) The driver of the vehicle
When installing a heat shrink tube over a cable, you should start at one end and heat
evenly working toward the other end to avoid bubbles from forming underneath the heat
shrink.
False
Duct runs are used to support cables along the wall of a manhole and maintain
separation between different cables.
False
Steel armors for cables are applied for mechanical strength and mechanical outer protection.
What is the disadvantage of steel armors on single conductor cables?
D) Magnetic properties of the steel affect the reactance of the circuit, which in turn affect the current carrying capacity of the cable
When working within a “contact area,” how many qualified personnel must be present?
B) Two
What device if installed at strategic points in an underground system will aid in identifying faults
or trouble locations?
B) zzzzz
Fault indicators
All ground level electrical equipment must be securely locked and or protected to
prevent the public, especially children from gaining access to energized parts.
True
What is the Xcel Energy standard burial depth for primary cable?
A) 30 inches
Is a Vaultman or Cableman considered a qualified person?
B) Yes
What is the following conductor shape?
C) Compact sector
What does underground triplex cable consist of?
D) Three insulated conductors with the neutral conductor being color-coded or marked in some manner for identification
What is used to spread irregular electric fields uniformly throughout the insulation on
underground cables to protect the insulation from concentrated electrical stresses around the
conductor?
B) Strand shield
Manholes are used for primary distribution or secondary distribution, never both in the
same hole.
False
Employee’s working in an excavation may not be closer than __________ feet to the
excavating equipment while it is in operation.
A) 15 feet
When removing semi-conducting material, why is it critical to make an even square cut?
D) Jagged edges can cause premature failure of the cable
What reduces the friction between the cable and duct walls, especially on curves in the duct run, by as much as 70%?
A) Cable lubrication
Why are cables racked along the walls of a manhole with large reverse curves formed in the
cables?
A) To allow for expansion and contraction of the cables due to temperature changes caused by changes in the power flow
Harmonics can increase power losses significantly in distribution circuits, causing major
increase in unaccounted for energy and operating costs.
True
Multi-conductor cables used for three-phase power circuits consist of three single
conductor cables with a common sheath or jacket.
True
When using live-line tools on energized cables or parts:
B) Only All doors shall be secured open before switching and Eye protection and rubber gloves shall be used
What is used in the interstices of cables to give the complete assembly a substantially circular
cross section?
A) Cable filler tapes
Why are duct runs between manholes installed at a grade that slopes gently toward one or
both manholes?
C) It allows water seepage to drain out of the duct
Outrigger pads are used to insure the truck body remains stable.
True
Which of the following is true in a common neutral system?
B) The secondary and the primary share the same neutral
What condition will increase the magnitude of induced current from a magnetic field on an
isolated, bracket grounded line?
D) The length of parallel between the two conductors is increased
When is the wearing of a company approved hard hat not required?
C) When working in the office or shop or while in a covered vehicle
What are the advantages of setting a recloser to non-reclose is that it provides for a faster
operation time?
D) The circuit will not be reenergized once it trips out
Ladders, ramps, ropes, or truck winch lines must be provided as a means of ingress
and egress in all excavations when shoring is used and must be provided every 20 feet
False
What type of insulation is used in shielded power cables, developed for experimental operation
at 230 and 345 KV?
C) Cross-linked polyethylene insulation (XLP)
A transformer that feeds series street light circuit is known as a:
A) Only Constant current transformer and Regulating transformer
When circumstances require that the loop feeds be served from different phases or feeders,
what must be installed at the opens in the loop feeds?
D) Appropriate warning tags
How many load break elbows are required to terminate the primary in a single-phase
transformer if it is between two other transformers?
D) Two
What is used to prevent injury to the cable by scraping on the manhole frame or at the duct
opening or in passing over other cables as it is being pulled into a duct run?
D) A feeding tube
When digging near energized primary circuits that are not protected by fuses, what should be done to make the operation safer?
B) Set the associated primary circuits on non-reclosing
What are the terms for large over voltages that develop suddenly on electric transmission and distribution circuits caused by switching operations or lightning?
A) Surges or transients
When work is performed in a manhole or unventilated vault, no entry shall be permitted until
the atmosphere is found safe by testing for what?
C) Only Hydrogen Sulfide & Oxygen deficiency and presence of explosive gasses or fumes
The visible light output from a street light lamp is measured in watts and the energy
input of a lamp is rated in lumens.
False
How is aerial cable supported?
A) The cable is attached to a tightly strung steel messenger cable with rings or lashing
What is normally used to terminate cables with solid dielectric insulation?
B) Molded rubber terminators
Specific hazards to a lineman when a socket-connected (S-base) meter is plugged into a meter
base with the top source energized are:
D) All the above
What is an advantage of an underground residential distribution system?
D) It is relatively immune to damage from lightning, wind, and ice
The size of the conductor has no affect the level of fault current at a work location when
working on a hot secondary circuit should a short circuit occur.
False
When working on underground energized conductive materials in condition C or above
live line tools shall be used. Under no circumstances should an employee’s hands
approach closer than two feet six inches to the energized end of the live line tool.
False
If a grounded vehicle were to become energized, the ground will prevent current from
flowing through a person that is in contact with the vehicle.
False
Insulation on unshielded cable, such as a covered conductor, cannot be depended upon for
personal safety because:
C) Only: The cover may have deteriorated without the deterioration being readily visible & It violates the manual of safe work practices
In pipe type cable construction, underground cable is pulled in to a pipe, which is filled with oil
that is continually circulated through the pipe. What is the purpose of the oil?
B) Only: Maintains high dielectric strength between the cable and the ground & Provides a cooling medium for the cable
Which of the following methods for assembling lattice steel towers is used when towers are
large and heavy and the ground is rough?
C) Piece by piece method: tower is assembled one piece at a time from the ground up
When installing a premolded straight and repair splice, the semicon shield must be
thoroughly cleaned with cable solvent.
False
What must be installed on the unused load break bushings in pad-mounted transformers and
connected separately to the ground bus with a hot line clamp?
B) An elbow arrester
Tracer wire shall be installed on all:
D) All the above
What is a precaution the cable splicer should take prior to beginning a cable splice?
A) Only Must maintain tools in good condition and keep them clean and dry Maintain clean dry hands, have drawings, and materials on hand
What device is used to keep the natural twist of the pulling line from causing the cable to twist
or rotate as it is being pulled in?
C) A swivel is installed between the pulling line and the cable
Identify the following conductor shape?
C) Segmental
What does the level of fault current at a work location depend on when working on a hot secondary circuit?
D) Only The distance from the work location to the transformer & The conductor size
Additional conductors shall not be pulled into a duct already occupied by an energized
conductor.
True
What type of surge arrestor is commonly found on a primary distribution system?
B) Distribution class valve type surge arrester
What should be done prior to switching primary cables in dead front 25 KV equipment to
provide an additional margin of safety?
D) Only Take precautions to insulate possible contact points in primary compartments Remove all debris (cobwebs, weeds) from switching area
Prior to shipping cable on a real, the manufacture is required to hermetically seal both ends of
the cable. How is this done?
A) By installing heat shrinkable polyethylene caps or hand tapping
When working in an excavation, stepping, standing or kneeling on energized
underground cables is prohibited unless protected with rubber protective equipment.
False
When opening an energized primary enclosure, what safety equipment shall be worn in
addition to safety shoes and FR shirts?
A) Hardhat, rubber gloves, and eye protection
What is a manhole?
D) It is an opening in an underground duct system which houses cable, splices, and allows access for testing, splicing, and pulling cable
What is the term for circuits that carry power from distribution substations to local load areas?
A) Express feeders, distribution main feeders, or primary circuits
What conditions for an excavation will identify the need for shoring, or providing the angle of repose to be sloped or benched to the correct angle as indicated on the excavation checklist?
D) The excavation is five feet or greater in depth or a competent person deems the excavation hazardous
What underground voltage condition applies to energized equipment known to be above
15,000 volts and not exceeding 44,000 volts phase to phase that do not fall under other voltage conditions?
C) Condition C
When will qualified personnel wear rubber gloves while engaged in energized underground distribution work?
A) At all times
When working on or near energized equipment, how must your shirt sleeves be worn?
A) Full-length sleeves must be secured at the wrist
What must be done to primary cables before they are cut?
A) Primary cables will be de-energized, tested and grounded at both ends and spiked before being cut
When ducts terminate in vaults, manhole or hand hole _________ are installed to create a
watertight duct entry system.
A) manufactured duct terminators or end bells
If a conduit run must be installed under a paved roadway, body of water, or an environmentally
sensitive area, what method can be used to accomplish the task and leave the surface
unmolested?
D) Directional boring method
Energized primary enclosures shall be attended by a qualified person while open and securely locked when closed.
True
Why should cables be pulled into a duct run slowly?
A) To allow for proper inspection and lubrication of the cable
When working on energized underground conductive materials in condition “b” or
above, approved live line tools shall be used.
True
What is the term for a hollow tube, made of plastic, fiberglass, fiber, tile, concrete, or steel, that runs from manhole to manhole in an underground electric system?
A) Conduits or ducts
Which of the following is true concerning cables energized at voltages at 600 volts or less
normal operating range?
A) They may be moved under the direction of the person in charge unless the cable is noticeably warm or the movement will cause a short radius bend
What is a template used for in transmission anchor construction?
B) A template is used to ensure the anchors are constructed to the dimensions that will line up with the lower portion of the tower
When an employee is in a manhole, a second employee is stationed on the surface near the manhole. What is the second employee’s purpose?
A) To pass material and be available to help or initiate rescue procedures
When untying energized conductors with hot tie sticks, you should cut the tie as close
as possible to eliminate the possibility of making contact with a different potential?
True
When using automated cable pulling equipment, the duct can be cleaned and the pulling line installed at the same time. How is this done?
D) The pulling line is attached to a double disk birdie, which is blown through the duct with compressed air
When energized conductor cables must be moved, how is this accomplished safely?
B) Both Rubber gloves and eye protection are worn and Live line tools, or non-conductive ropes or slings are used
The insulation best suited for a specific cable depends on many factors. Which of the following
are factors considered?
D) Operating voltage, current load, type of installation, and ambient temperature
Network protectors in service that are found in an “open” position and will not “close”
automatically should be closed manually as soon as possible to avoid a possible
outage.
False
Which type of sheath has experience shown to be the most effective protection for insulation
against moisture, weather, and oxidation?
B) Intact lead
Prior to entering a manhole, what should employees inspect the interior for?
D) All of the above
What causes fault indicators to trip?
D) A high magnetic field due to fault current
On underground cable, what would cause the cable to fail prematurely due to voltage induced
electrical stresses?
D) All the above
Stringing a fourth conductor on a delta system and changing the transformer connections from delta to WYE increases load carrying capacity _________%.
A) 73
Protective creams shall be used to protect skin when exposed to askarels, joint compounds, pulling compounds or similar skin irritants.
True
When a faulted cable is exposed for repair, what should be done before the cable is handled?
D) All of the above
“Contact area” is defined as any location within or from which the worker’s body is within
reaching, falling, or extended reach of energized conductive materials beyond stress relief and has a potential of ___________ normal operating range.
B) 650 V
Splices should be installed in transformer cabinets or basements to allow for extra slack for switching.
False
All primary cables in a manhole or vault shall be fireproofed with an approved fireproofing tape such as Scotch 77.
True
What can be placed in trenches to mark the location of underground electrical facilities?
A) Red or yellow marker tape, and/or marker balls
Why are terminator ground wires routed a minimum of three inches away from metal brackets on a terminal pole?
A) To prevent radio interference
What is a two-way manhole?
D) An underground chamber where cables enter or leave in only two directions
On single-phase riser poles, terminators can be placed on the same pole with a
transformer as long as they are provided with wildlife protection and arresters.
False
What is the maximum number of U-guard runs, including foreign utilities, that can be on a riser pole, not to exceed 40 % of the pole circumference?
B) Three
A properly installed shield wire is highly T F effective if the ground resistance is high.
False
When two people are working on energized conductors on the same structure, only one phase can be worked at one time.
True
Why is it recommended that there are no more than nine ducts per duct run?
C) When a greater number is used the heat radiation per cable becomes greatly reduced
To eliminate high voltage at the secondary terminals, what should be done prior to removing
the load from an energized CT?
A) The secondary terminals should be shorted out
There are two methods of grading the slope of a duct run to allow water to drain from the duct. What are they?
B) Double slope and single slope
Why must cable shields be grounded and maintained near ground potential?
A) Only For the safety of the linemen and cablemen and For the protection of the cable
Lattice steel or aluminum towers can be assembled in a marshaling yard and flown by
helicopter to the line location where they are set on previously installed footers or
anchors.
True
When inspecting a rubber line hose you should roll it inside out and look for:
D) All the above
en preparing a cable for splicing, it is critical that all traces of __________ be removed from the insulation back to within the approximately 1/4 inch of the metallic shield.
C) semi-conducting material
On a circuit that is grounded, the worker becomes part of a series circuit to earth.
False
What piece of equipment prevents high voltages from building up on a circuit by providing a
low impedance path to ground for the current from lightning or transient voltages, and then
restores normal circuit conditions?
C) A surge arrestor
What is the most common type of transformer used in underground residential distribution
systems?
B) Pad mounted transformer
The “C L O R” on a CSP transformer breaker handle stand for Closed, Light, Open,
Reset
True
Varnished cambric insulation tends to have a low power factor and high ionization level
and it must be covered by a lead sheath for moisture protection if used on a cable in a non-protected atmosphere.
False
How are shielded power cables generally manufactured?
B) Conductor, conductor strand shielding, insulation, semi-conducting insulation shield, metallic insulation, and a sheath or jacket
Which of the following is a reason for installing an underground system?
D) All of the above
Another term to describe aerial spacer cable is:
B) Tree wire
On a current transformer, what happens to the voltage when the current is stepped down?
A) The voltage increases at the same ratio
What are disadvantages of an underground residential distribution system?
D) All of the above
Which type of primary neutral system is connected to ground at a minimum of four locations
per mile?
A) Multi-grounded neutral system
What happens when a conductor’s temperature reaches the annealing point?
A) Only The conductors strength is permanently changed and The conductors brittleness and elasticity are permanently changed
Manholes are constructed on site or pre-cast and transported to the site.
True
Identify the following conductor shape?
D) Annular
What is provided for cables operating at more than five KV to ground and is recommended for cables operating above two KV to ground?
D) Insulation shielding
Why is the space between the conductor strands in cables, filled with a semi-conducting
compound during the manufacture of the cable?
D) To prevent water from penetrating the stranded conductor which can cause damage to the insulation and premature failure of the cable
What type of insulation consists of a vulcanized vegetable oil and bitumen base, which is,
compounded with other ingredients to form an ozone resistant insulation?
D) Oil based rubber insulation
What must be done to ensure that a mechanical jumper is carrying enough of the load to safely cut the conductor that is jumpered out?
C) An amp check must be performed to ensure that the mechanical jumper is carrying at least 30% of the load
Which of the five shapes of stranded conductor cable are designed to reduce “skin effect?”
A) Annular and segmental
Pre-cast manholes can be fabricated in the __________ configuration and are transported to the job site in sections.
D) All the above
What part of the cable confines the dielectric field within the cable to obtain symmetrical radial distribution of voltage stress within the dielectric?
D) Cable insulation shielding
Why are secondary cables for underground installations generally larger than those for
overhead applications?
B) Because of reduced capacity of the cable due to temperature limitations of the cable insulation
Identify the following conductor shape?
C) Compact round
What is normally used to splice cables on underground distribution systems that are direct buried?
C) A prefabricated cable splice kit is used to splice the cable
Working on a bracket grounded conductor is similar to working on a neutral conductor; the
voltage may be low but there could be substantial __________.
D) current flow
Why is underground cable in subdivisions installed in a loop feed?
D) It allows faulted cable to be isolated so service can be restored to the customers prior to making repairs
In an underground pad mount transformer, load break elbows are used to connect
cable to the X1 and X2 bushings.
False
Conduit installed through a building wall is equipped with which of the following to prevent gas from entering the building?
A) Internal and external seals are installed, sometimes supplemented by gas venting devices that reduce positive gas pressure in the conduit
Why is a weather head used on vertical conduit?
A) To prevent rain from entering the conduit
When preparing underground cable for splicing, what is done to the ends of the factory
insulation to avoid creating a direct radial creepage path from the conductor outward?
C) The ends of the factory insulation facing the connector are penciled or stepped
Electrical burns will occur if contact is made with a hot circuit and no other part of a
person’s body is in contact with another object at a different potential.
False
When referring to wire types, what does the abbreviation AAC stand for?
A) All Aluminum Conductor
Why do many of the high-voltage cables, with a concentric neutral conductor, have a semi-conducting polyethylene jacket extruded over the concentric neutral conductors?
C) To prevent electrolysis of the concentric neutral conductors
What is the following conductor shape?
B) Concentric round
If two cables of identical size are installed, the direct buried cable will have a greater
ampacity than the cable installed in conduit.
True
Neoprene compounded sheaths are frequently used on heavy-duty portable cords and
cables.
True
Why is a semi-conducting, polyethylene jacket extruded over the concentric neutral conductors of many high voltage primary underground cables?
D) To prevent electrolysis of the concentric neutral conductors
Which of the following is a method for keeping a manhole free of water?
D) Installation of a pump or gravity drain connected to a sewer system
What is a pre-cast manhole neck used for?
D) It is used to extend the manhole opening to the proper level for the surrounding area
Is it never permissible to inspect pressurized hydraulic lines by sliding your hands over
them.
True
When hot line work or live line work is to be done what should be done to the source circuit
breaker or the recloser?
A) Only The automatic reclosing feature should be blocked and The automatic reclosing feature should be tagged
Which of the following sheath materials provides mechanical protection to the cable and may
also function as a current return?
C) Lead
In order to protect a distribution line worker from a second point of contact when performing
hot work, he must:
D) All the above
When installing direct buried cable, which statement is true concerning the bottom of the
trench?
C) Only The trench should be relatively smooth and The trench bottom should be undisturbed, well-tamped earth, or sand
Which cable jacket material has excellent resistance to acids, alkalies, cutting, flame, moisture, oils, ozone, sunlight, and weathering?
B) Polyvinyl chloride (PVC)
When routing conduit, what types of soil should be avoided?
D) Unstable, shifting soil, or corrosive soil
How is the pulling line attached to a cable that is to be pulled through a conduit duct?
B) The pulling line is attached to the cable with a woven cable grip, clevis, or eye
Identify what type of manhole is illustrated?
C) Three way
Approximately how much voltage does the ballast for a high-pressure sodium bulb supply to start the arc in the lamp?
B) 2500 volts
What are the three most common materials used as insulation for power cables?
A) Taped insulation, rubber or synthetic compounds, and thermo-plastics
Why are stranded conductors used in large power cables?
C) Stranded conductors cables are more flexible and easier to bend
Harmonics can increase power losses significantly in distribution circuits, causing major increase in unaccounted for energy and operating costs.
True
In transmission tower construction, what is the purpose of the anchors?
C) Anchors support the tower and prevent them from blowing over when the lines are subjected to sleet and wind
What is the term for a flared opening that makes it easier to pull the cable and eliminates the sharp corner that might injure the cable sheath as the cable is pulled in?
D) Conduit or duct bell
How are underground power cables generally classified?
C) Shielded and non-shielded
What is considered in the design and construction of conductors, insulation, sheath, jacket, and shielding for underground cable installation and operation?
A) Mechanical, thermal, environmental, and electric stresses
Given a nine duct conduit run that is completely empty and four power cables, a lineman should install the cables in the middle ducts to protect the cables by reducing
heat radiation.
False
What is a submersible transformer?
A) A transformer designed to operate under water
What are vaults?
A) Large manholes used for transformer and network protector installation
Which type of insulation is limited to low voltage applications (600 volts or less) due to power factor and dielectric losses?
C) Polyvinyl chloride (PVC)
Primary underground cables must never be installed in the same trench with secondary
underground cables.
