When operating pole mounted switches, what should they be inspected for each time they are operated?
D) All of the above
The larger the transformer feeding the circuit, the greater the ability of the system to supply high fault current.
False
Where would you find the highest available fault current?
A) Near the substation
Specific voltage ranges must be met by a utility when supplying power to a service. Where is this measured?
B) At the point of delivery, usually at the meter base
What type of charge (if any) can remain in a cable after it has been de-energized?
B) Capacitive
What do defective insulators cause?
C) Visible corona and radio interference
A normally open cable in a padmount transformer can be closed as long as it is of the same phase.
False
In a substation, to decrease the chance of a worker in the station yard getting between two different potentials, what pieces of equipment are bonded to the grounding network?
D) All of the above
The purpose of a no-load tap changer is to be used while energized, but load is removed.
False
Identify the following Auto Cad symbol.
A) Wire Type Change
What is created in the atmosphere by the friction between particles of rapidly moving air?
B) Electrical charges
On the Smallworld mapping system, a triangle with “YY” on the left side and “ABC” on the right side indicates a _______________ transformer bank.
D) Three-phase WYE-WYE
Oil with no moisture content would be a __________________.
A) insulator
Low voltage can cause ___________.
D) All of the above
Which of the following is a protective zone of the transmission protective scheme?
D) All of the above
The _________________ detects current entering a protected zone does not equal the current leaving the zone and is one type of relay that controls transmission circuit breaker operation.
A) differential relay
Employees must remember that they enter a customer’s property by invitation and should consider themselves a guest. Care shall be taken to
________________________.
D) not track in mud and snow, and protect floors and floor coverings
What causes electrochemical treeing in cables with solid dielectric insulation?
A) Water in the conductor that penetrates the insulation
What is the Sparkover effect of a voltage surge?
D) A disruptive discharge through the air
The high-voltage tap changer is designed for de-energized operation only.
True
Identify the following Auto Cad symbol.
B) Switch cabinet
The abbreviation TCC refers to Time current characteristic when speaking of protective equipment in a circuit.
True
All switched capacitor banks should be inspected and checked for proper operation once each year prior to the time period they are automatically switched on and off.
True
The standard 120 volt AC nominal voltage must be maintained between what range of values?
C) 114-126 volts
Substation circuit breakers automatically provide opening and closing under fault conditions.
True
Identify the following Auto Cad symbol.
B) Open transformer
How often is a shield wire grounded?
B) At each structure
Why is the neutral mounted above the conductors on static neutral or vertical construction?
A) It provides protection from lightning for the phase conductors
Underground circuits and cables have their own unique problems, such as:
A) Both Moisture and corrosion, and Cable “dig ins” and insulation failure
Sources of secondary backfeed are not always obvious and include the following:
D) All of the above
On a standard North American single phase service, the service and the meter are either the two-wire or three-wire type
True
Customer’s equipment can be damaged by either high or low voltage.
True
Most of the underground distribution circuits tapping the main circuits are what?
B) Single phase loops
On an electrical system that is properly grounded, meaning that all of the neutrals and wye connected transformers are run to earth through grounds, what happens to the voltage on the grounds when there is an unbalanced load?
B) The voltage increases
What does most insulator damage result from?
C) Gunshots, wind damage, contamination, and lightning flashovers
Most residential and smaller businesses are supplied with three (3) phase
services.
False
Overvoltage protection does not involve ensuring that a voltage surge will not exceed the BIL rating of the equipment or line that it is protecting.
False
For what reason is protective equipment installed in a circuit?
D) All of the above
When inspecting distribution equipment installations, the inspector should observe, record, and recommend repairs for the following equipment issues.
D) All of the above
The amount of fault current that flows through the complete circuit when a fault occurs depends on what?
D) All of the above
The _________________ detects voltage change beyond predetermined limits and is one type of relay that controls transmission circuit breaker operation.
C) over-or-under voltage relay
When a lineman or patrolman is looking for trouble on a line they should always obtain a clearance prior to their patrol.
False
During an over-current situation, a line crew is called out after circuit breakers,
reclosers, sectionalizers, or fuses have gone through their sequences and have isolated any circuits with a permanent fault.
True
Substations can be ________insulated.
A) Both gas & air
Energy is the amount of power used over time measured in kWhs. For example, the energy used by ten (10) 100-watt lights after one hour would be one (1)
kWhr.
True
There are generally three (3) types of charges a customer can be asked to pay. What are they?
D) Energy charge, capacity (demand) charge, and customer charge
What type of substation converts AC to DC and then back to AC again?
B) A converter station
Lighting is the most frequent cause of _____________ and one of the most transient faults on an electrical system.
C) over voltage
What is a transient fault?
C) A temporary fault
Line reclosers should not be installed with bypass switches, they do not require maintenance.
False
A single line diagram provides a quick method whereby a lineman or cableman may analyze the complete facilities in schematic form.
True
What is the potential gradient on the ground, per foot, of a lightning discharge within the clouds that never reaches the earth?
D) Up to 3 KV per foot
What are the three (3) kinds of loads fed by an AC Circuit?
C) Resistive, inductive, and capacitive
What is the outcome when air becomes electrically stressed and breaks down resulting in a high voltage and high current discharge between the positive and negative charges?
A) Lightning
The purpose of a shield wire is to be the most attractive element for a lightning strike.
True
A surge arrester should be well grounded and as close as possible to the
equipment it is protecting.
True
The rate of the rise and fall of the voltage and current and the direction of flow can be represented on paper by drawing a sine wave.
True
The _________________ relay detects changes to the reactance in a circuit beyond predetermined limits and is one type of relay that controls transmission circuit breaker operation.
A) power factor relay
When a circuit has been out for a while, especially during peak-load periods there is a possibility of a high initial rush of current when the circuit is closed in. This initial high current can trip the line out again.
True
Name what conditions will occur if there is an over current situation and there is no protective scheme to isolate it.
D) All of the above
Identify the following Auto Cad symbol.
D) Man hole
In North America, AC supplied by electrical utilities travels ____ times in each direction in one second. In certain parts of the world 50(Hz) cycles per second is common.
D) 60 (Hz)
The source for Tingle Voltage, a DC voltage is found between the neutral and earth. This is likely caused by ________________.
A) communication circuits or cathodic protection on a nearby pipeline
Reversed reactance compensation is a method used to reduce the circulating current that might flow when two or more transformers are paralleled.
False
Which of the following types of faults or combinations of faults can transmission protective relays detect if they show up and are measured at their terminals?
D) All of the above
The _________________ can detect a predetermined difference between two circuits or between phases on a circuit and is one type of relay that controls transmission circuit breaker operation.
A) current or voltage balance relay
A(An) ____________ tag is used to identify a cable that has faulted and is in need of repair.
A) Information Tag
Alternating current (AC) became the standard form of electrical power over direct current (DC) in the pioneer days of electrical power. Alternating current has one major advantage:____________________________
C) the easy transformation from one voltage to another
Lightning that is discharged in the clouds, but never reaches the earth, can still energize an isolated conductor.
True
On a wye –wye transformer bank the primary neutral must be connected to the secondary neutral.
True
If you saw the following drawing on an electrical print, how would you identify it?
D) As an oil circuit breaker
Transmission and distribution line inspectors will detect damaged insulators. Most insulator damage will result from what?
D) All of the above
What is the Puncture effect of a voltage surge?
A) A disruptive discharge through a sold material such as rubber cover up, rubber gloves, or a fiber conductor cover
Aerial patrols are often initiated if a transmission line has an unscheduled outage to locate problems such as _________.
D) All of the above
The secondary and service cables used for underground electric distribution are generally larger than those used in overhead systems because of reduced capacity for a given conductor. This is a result of what?
C) Temperature limitations of the cable insulation
When ferroresonance occurs, the voltage can build up from 5 to 15 times the normal phase to ground voltage. The increase in ___________ is evidenced by a loud hum, whine, or rumble from a transformer during switching, flashovers at terminals, insulators, switchgear; and failure of lightning arrestors.
A) voltage
Sectionalizers are capable of working independently of any other protective equipment.
False
A fault may be a dead short or a partial short depending on the impedance between the energized conductor and the object causing the short.
True
What type of fuse is the bayonet fuse, which is used, in single-phase underground transformers?
A) Primary
A phase-to-ground fault is the cause of about 70% of permanent faults. Which of the following is a probable cause?
D) All of the above
The resistance of a driven ground should be below ____ ohms.
D) 25
Transmission and distribution lines where experience indicates conductors have prolonged periods of vibration should have _______ installed to prevent fatigue failure of the conductor.
B) vibration dampers
What procedure is used before approaching the danger zone in a switch cabinet?
D) Isolate, test, and ground
Lightning can induce a voltage of up to _____________if the line is isolated?
C) 100 KV
Transmission and distribution lines can be inspected with infrared scanning equipment to locate hot spots on conductors and equipment caused by loose connections or hardware, and other defects.
True
What is the step and touch potential per foot for people in the immediate area of a lightning strike?
A) Up to 70KV per foot
Never pound with a hammer, or visually inspect a wooden pole before climbing.
False
Which of the following is an advantage of a higher voltage distribution system?
D) All of the above
Switchgears for underground electric distribution circuits should be inspected
___________.
D) every year
Resistance is the largest component of total impedance to current flow in a circuit.
True
Once completed and in service, a riser pole for an underground distribution circuit does not need to be inspected or maintained.
False
At what voltages do transient voltages usually become significant?
D) 230KV and above
What type of arc suppression that is used in substation circuit breakers is the most common?
C) Oil
Group- operated or single pole switches installed in overhead distribution lines should be checked each time they are operated by a lineman for which of the following?
D) All of the above
When inspecting distribution pole-top assemblies, the inspector should observe, record, and recommend the following repairs of pole- top issues.
C) Both broken, burned, or damaged pins/ or cross arm requiring replacement & broken skirt of pin type insulators
When inspecting distribution guy wires, the inspector should observe, record, and recommend the following repairs of guy-related issues.
B) Slack, broken, damaged, or improperly installed guys
The potential on a system neutral should be less than ____ volts.
B) 10
When inspecting distribution poles, the inspector should observe, record, and recommend repairs for the following pole issues.
B) Broken or damaged poles needing replacement
After the initial inspection is completed, and once the transmission line is
energized it never needs to be inspected again.
False
All transmission lines should be thoroughly inspected after construction is
complete, and before energizing the line.
True
A phase-to-phase fault is a high impedance fault.
False
In a balanced three phase circuit, where does the return current flow?
C) Phase conductors
Switched capacitor banks and Reclosers only need to be pulled for maintenance when the number of operations reaches a preset number. Periodic maintenance is not required because they do not operate all the time.
False
What does a load drop compensator try to maintain?
C) It maintains voltage at 100% near the center of the load on the line
The regulation or control of voltage on a distribution system is usually accomplished by
a combination of two different methods. What are they?
A) Only Transformer tap changing equipment, step voltage regulators, and induction voltage regulators & Capacitors
B) Transformer tap changing equipment, step voltage regulators, and induction voltage regulators
C) Capacitors
D) Reclosers, fuses, switches, and sectionalizers
A) Only Transformer tap changing equipment, step voltage regulators, and induction voltage regulators & Capacitors
Identify the following Auto Cad symbol.
B) A capacitor
A distribution substation will have either a circuit breaker or recloser prior to the feeder leaving the station.
True
Fuses are chosen for a specific location dependent on what attributes?
C) Size of the fuse & its Speed Rating
A transformer with a partially shorted coil could result in high secondary voltage.
True
In a distribution system, protective equipment is placed sat strategic locations to limit and isolate faults so the remainder of the system is not affected.
True
A step-down transmission substation is also a switching station where lines from different parts of the grid come together.
True
How does a poor return path for current to flow affect a distribution protective scheme device?
A) It reduces the current flow in the circuit and reduces the current flow through the protective device
Identify the following Field Smart symbol
A) Fault indicator
Voltage surges from lightning travel in only one direction on a conductor,
dependent on the polarity of the lightning bolt.
False
The available fault current at the source of a feeder is based on what information?
A) Both Impedance and size of the distribution substation transformer & Voltage, conductor size, and length of the circuit feeding the substation
All known faulted cables must be grounded prior to connecting test equipment.
True
The _________________ detects an abnormal rise in the temperature of a generator or transformer and is one type of relay that controls transmission circuit breaker operation.
A) thermal relay
Before receiving a clearance to begin switching out a piece of equipment that you intend to work dead, what must you do first?
D) All of the above
Voltage regulation on any electrical system is defined as _________.
D) the difference in voltage between periods of no load, and full load
The _________________ detects current when it exceeds predetermined limits and is one type of relay that controls transmission circuit breaker operation.
A) over current relay
When dead-ending a three-phase line of #2 ACSR, horizontal construction, how many wooden cross arms are needed to complete the task?
D) Two
What is defined as the voltage level that can flash over the leakage distance of an insulator?
D) Basic Impulse Insulation Levels
The purpose of a shield wire is to be the most attractive element for a lightning strike.
True
Once the control schematic diagram is understood, it is easy to apply the
information to some portion of the associated wiring diagram.
True
______________________ refers to the indirect method of keeping voltage at a proper level. Voltage is regulated by ensuring that the conductor size and distance and power factor of a circuit are adequate.
B) Voltage regulation
What does the following Auto Cad symbol indicate?
A) 200 Amp switch cabinet dead front
Capacitors control voltage by supplying lagging current to a distribution line to counteract the leading current, which the line must supply to magnetize motors, transformers, and other magnetic equipment.
False
A recloser will provide protection for any circuit that has the capacity
downstream to generate the needed fault current to trip it.
True
What is used in substations to counterbalance the excessive inductive reactance produced by customer load and large transformers?
B) Capacitor banks
Of the air-insulated and the gas-insulated substations, which is the most common?
C) Air-insulated substation
Which of the following are true when the bayonet fuse on an underground single-phase transformer is removed?
D) Both secondary and primary transformer windings will be de-energized
In an unbalanced three phase circuit and single phase wye distribution, where does the unbalanced current flow back to the source?
C) Neutral
A short circuit is when the _____________ between an energized conductor and another element that are in contact with each becomes low enough.
C) impedance
On a long line that is lightly loaded, capacitive charging current may exceed the load current and result in the receiving end voltage being greater than the sending end voltage.
True
What determines the extent of voltage regulation required for a particular system?
B) Characteristics of the system and the amount of load
Tap-changing equipment and voltage regulators are widely used in the industry to maintain voltage ranges within acceptable levels.
True
What part of the power grid may have one or more sub-transmission lines, two or more transformers, and multiple outgoing distribution feeders associated with it?
C) Distribution substation
Linemen should periodically inspect the routes of underground electric cables, for obstacles that could damage the cables. Which of the following are things that the lineman should look for?
B) Changes in grade or washouts that might expose or damage the cable
What is the cause of about 70% of the permanent over current faults on a distribution system?
D) Both phase to ground fault & phase to neutral fault
Regulators generally provide for a variation in load from 10% below to 10% above normal line voltage. This is accomplished by which of the following?
A) 32 steps of 5/8%
Which voltage regulation component has the ability to reduce the KVA load on lines, transformers, and generators, making them available for load growth?
B) Capacitors
What can be used to locate hot spots caused by loose connections, hardware, or other defects on a line?
C) Thermo-vision or infrared scanning technology
What happens to the voltage on a phase conductor and the neutral if a voltage surge is great enough to have a coupling effect between the two?
C) Voltage on the phase is reduced and voltage on the neutral is increased
Identify the following Auto Cad symbol.
B) Fused Switch-Closed
What are advantages of SF6 and vacuum substation breakers over oil filled?
D) All of the above
The time-current characteristics of protective devices are used to coordinate the tripping time of one protective device with another.
True
transformer output with transformer taps or changing the feeder voltage with line voltage regulators.
B) Voltage Control
What does the following Auto Cad symbol indicate?
D) Primary metering
What is used in a substation to add inductive reactance to balance the capacitive reactance that is generated by very long extra-high voltage lines?
D) Substation reactors
What reasons for momentary disturbances could affect power quality?
D) All of the above
Some customers own a UPS system which is a backup power supply to keep them from experiencing even momentary outages. What does UPS stand for?
B) Uninterrupted power supply
Which of the following is an effect that a voltage surge can cause on a circuit?
D) All of the above
The _________________ detects frequency when it changes abnormally and is one type of relay that controls transmission circuit breaker operation.
A) under or over frequency relay
Electrically connecting the neutrals of every wye connected transformer and generator to earth is known as what?
C) System grounding a power system
What is used to generate inductive reactance?
D) Substation reactor
Identify the following Auto Cad symbol.
C) Booster / regulator bank
Where do arresters need to be placed so they are the most effective?
A) As close as possible to the equipment they are protecting
The resistance of a fault affects the amount of fault current that can flow through a circuit.
True
How many fuse bays does a PMH-10 have?
A) None
Which of the following disturbances can affect power quality?
D) All of the above
Identify the following Auto Cad symbol.
A) Recloser
Other than a lightning surge, what are the main types of faults in an electrical system that causes a circuit breaker to operate?
D) All of the above
The substation yard is a zone of equipotential due to the fact that everything is tied to the grounding grid within the station.
True
The substation yard is constructed to actually be an equipotential grid.
True
What is the most frequent cause of transient voltages?
A) Lightning
Some characteristics of lightning are?
D) All of the above
The use of voltage- regulating equipment is made necessary because of a
characteristic common to all electric circuits. This characteristic is called impedance. Impedance is defined as ________.
D) the opposition to the flow of current in an electric circuit
Because load changes constantly, an electrical system should be designed so that the voltage regulation does not exceed a range of_____________.
A) 2% to 3%
Transmission protective relays can detect a fault only if measurable conditions show up at the terminal points of the circuit.
True
On a multi-grounded neutral system, how much fault current would flow to the source through the earth?
A) One third
The _________________ detects current when it has decreased beyond a
predetermined limit and is one type of relay that controls transmission circuit breaker operation.
B) undercurrent or under power relay
The grounding grid in substations is usually made up of what type and size of conductor?
D) 4/0 bare copper
What is the most common cause of over voltages and transient faults on an electrical system?
B) Lightning
How are high voltage conditions detrimental to the operation of electrical equipment?
D) Shortens the life span of heating elements, light bulbs, and electron tubes
In a copper to aluminum connection, the copper is placed on top to prevent the aluminum from leaching and corroding the copper.
False
When the temperature of the earth decreases and the moisture in the earth freezes, what happens to the earth’s resistance?
B) Increases
When electrical equipment is connected to a system ground, what happens to a voltage surge?
C) A voltage surge would be kept to a lower level and dissipates quicker
Switching on an electrical system causes transient over voltages.
True
Submersible transformers are inexpensive to install and maintain, this makes
them more widely used than pad mount transformers.
False
Pad-mount transformers are used more extensively than other types of
underground transformers.
True
A surge arrestor is a device that allows surge current to go to ground and
dissipate and then stops the current flow before it becomes a ground fault.
True
A clearance tag is used to inform another person approaching the job that you are rubber gloving energized conductors downstream of that particular device.
False
What are the basic feed types of electric underground and overhead circuits?
D) All the above
What is the purpose of a schematic diagram?
D) All of the above
Frozen ground around part of a ground rod can double or triple the resistance
True
How many control spans should be used in a sag section consisting of seven spans?
A) Two
A __________ is part of the electrical circuit and is a current carrying conductor that provides a path for current to flow back to the source.
A) neutral
Identify the following Auto Cad symbol.
C) Split bus ATO
The _________________ relay detects a change in the direction the power is flowing on a circuit within the grid and is one type of relay that controls transmission circuit breaker operation.
C) directional power relay
Fault current does not need a complete circuit to flow.
False
When the load in an electrical system increases, what happens to the voltage at the load?
B) It decreases
Three- phase pad- mounted transformers are available with what secondary voltages?
D) All of the above
In an electrical protective scheme, what piece of equipment has the lowest BIL rating?
D) A surge arrestor
Other than lightning, Short circuits and open circuits are the two main types of faults in a transmission electrical system that will cause a circuit breaker to operate.
True
The timing sequence of a recloser is coded as follows:
D) A = instantaneous, B = retarded, C = extra retarded, D = steep retarded
Lighting is part of an electrical circuit between the earth and atmosphere.