EOG 300 pg67-71 Electrical System Response

Questions and Answers

Which statement accurately describes the characteristics of transmission lines?

They exclusively carry electricity within city limits.

They are supported exclusively by underground structures.

They operate at a maximum of 250,000 volts.

They must have at least six insulators. (correct)

What voltage level is characteristic of Tulsa's transmission lines?

450,000 volts

345,000 volts (correct)

120,000 volts

75,000 volts

Where can transmission lines be found?

Only in rural areas and not within city limits.

Only at generation sites.

Both in city limits and leading to substations. (correct)

Exclusively over water bodies.

How can one identify transmission lines?

By the number of insulators they possess. Signup and view all the answers

What role do transmission lines serve in the electrical system?

They transfer electricity from generation sites to substations. Signup and view all the answers

What is the maximum voltage that the distribution lines can carry?

34,500 volts Signup and view all the answers

Which material is NOT mentioned as being used for distribution lines?

Titanium Signup and view all the answers

Which of the following statements is true regarding the coating on the distribution wires?

It protects the wire from wear, chaffing, and corrosion. Signup and view all the answers

In what type of neighborhoods are the buried distribution lines predominantly found?

New residential neighborhoods and apartment complexes Signup and view all the answers

Which type of wire configuration can be used for distribution lines?

Single strand or stranded Signup and view all the answers

What is the primary function of substations within an electrical distribution system?

To reduce voltage and send it into the distribution system Signup and view all the answers

Why are substations typically fenced-in areas?

To restrict access and enhance safety Signup and view all the answers

What aspect of voltage is highlighted regarding substations?

Voltage is reduced before entering the distribution network Signup and view all the answers

Which of the following is NOT a characteristic of a substation?

Direct generation of electricity Signup and view all the answers

In the context of the electrical power system, what is the significance of voltage reduction at substations?

It allows for easier transport of electric power over long distances Signup and view all the answers

Which type of transformers are designed specifically to reduce voltage for consumer use?

Pad mounted transformers Signup and view all the answers

What is a significant hazard associated with subsurface transformers?

Restricted space inside vaults Signup and view all the answers

When will TFD personnel enter underground vaults to combat fires?

When accompanied by a PSO Signup and view all the answers

Which of the following transformer types is NOT explicitly mentioned as being aerial or pad mounted?

Subsurface transformers Signup and view all the answers

What common factor is shared by aerial and pad mounted transformers?

They reduce voltage for customer use Signup and view all the answers

What is the primary function of the service connection in the distribution system?

To deliver power from the distribution system to the customer. Signup and view all the answers

Which type of wiring is most commonly used for service connections in residential structures?

Triplex wiring. Signup and view all the answers

How many wires in the triplex wiring carry voltage, and what is their voltage rating?

Two wires at 120 volts each. Signup and view all the answers

Through which structure does the service connection typically enter a residential building?

The weatherhead or conduit. Signup and view all the answers

What protects the service wires as they enter a structure?

The weatherhead. Signup and view all the answers

What is the primary cause of step potential risk when walking near a downed energized wire?

The varying voltages between two points underfoot Signup and view all the answers

Which of the following actions is recommended if a responder finds themselves in a step potential situation?

Bring both feet together and hop away Signup and view all the answers

What factor does NOT affect the extent of the grounded field near a downed wire?

Time of day Signup and view all the answers

In which scenario would a responder MOST likely experience tingling sensations in their feet?

When exposed to a lower voltage near a downed wire Signup and view all the answers

What is the main characteristic of ground gradient related to electrical hazards?

It represents a decreasing current emanating from the point of contact Signup and view all the answers

What precaution should be taken when responding to a manhole that is smoking or on fire?

Beware of the cover becoming airborne due to an explosion. Signup and view all the answers

Where can one find the manual for the Wilbur TAC stick?

On the Intranet in the designated folder. Signup and view all the answers

Under what circumstances should the TAC stick be used?

Whenever a company responds to lines down. Signup and view all the answers

What should happen before TFD enters a manhole to fight a fire?

PSO must be on the scene. Signup and view all the answers

Which of the following is not true regarding manholes?

They are safe for entry without precautions. Signup and view all the answers

What happens to an electrical wire during installation when it is unrolled from a cable spool?

It exhibits a tendency to recoil. Signup and view all the answers

How many times can a recloser attempt to restore a circuit after it initially opens due to a fault?

Four times Signup and view all the answers

What should be considered when checking a downed wire?

The wire may become energized unexpectedly. Signup and view all the answers

What is the potential hazard when an object falls on a wire under extreme tension?

The wire could whip back towards the connection point. Signup and view all the answers

What is the function of a recloser or line restorer?

It waits and tests a circuit after a fault. Signup and view all the answers

Within the city limits of Tulsa what is the percentage of underground distribution lines from PSO?

35% Signup and view all the answers

Study Notes

Electrical System Overview in Tulsa

Transmission lines transport electricity up to 345,000 volts, primarily from generation sites to substations.
Transmission lines can be identified by having at least six insulators and may be located within city limits, supported by towers or poles.
Substations, fenced areas, reduce voltage for distribution; they serve as critical nodes in the electrical system.

Distribution Lines

PSO maintains around 35% of distribution lines below grade within city limits, primarily in new residential areas and apartment complexes.
Distribution lines carry voltages up to 34,500 volts and are typically made of copper, aluminum, or aluminum-coated steel.
Insulating-looking coatings on distribution wires protect against wear and corrosion but are not actual insulation.

Transformers

Transformers reduce voltage to a usable level for customers; they can be aerial, pad-mounted, or subsurface, the latter often located in vaults.
Responders face hazards when dealing with subsurface transformers, particularly in confined spaces; TFD personnel require PSO presence for safety in emergency situations.

Service Connections

Service connections are the final part of the distribution system, delivering power to customers.
Wiring typically enters residential structures through a weatherhead or conduit, often using triplex wiring (three wires twisted together) carrying 120 volts and one neutral wire.

Electrical Hazards

Ground Gradient

Downed energized wires create a ground current and a hazard zone where voltage potential decreases concentrically from the point of contact.
Ground moisture and voltage determine the extent of the energized field, which can extend several feet and pose risks.

Step Potential

Step potential occurs when responders walk near downed wires, creating a circuit with differing voltages, increasing shock risk.
Tingling sensations or severe injuries can result from contact; responders should keep feet together and hop away from hazardous areas.

Cable Installation Considerations

Electrical wire has a "reel memory," tending to recoil towards its original winding direction during installation, which can be dangerous if under tension due to fallen objects.

Line Restoration Technology

Reclosers automatically detect problems in downed lines, attempting reconnection multiple times before needing manual reset; maintain caution while testing with a TAC Stick as circuits may appear inactive yet become re-energized.

Manholes Safety

Manholes serve as splice points for PSO wires and are considered confined spaces; explosions can cause covers to be ejected.
TFD will not respond to manhole incidents without PSO present due to potential dangers.

TAC Stick Guidelines

The TAC stick manual, accessible through the Intranet, provides operation and limitation guidance; it is essential for any company responding to downed electrical lines.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

This quiz explores the intricacies of Tulsa's electrical system, focusing on the transmission lines that carry high voltage electricity. Examine the infrastructure that supports these crucial components of energy delivery and their role within urban limits. Test your knowledge on strategic and tactical considerations involved in managing electrical systems.

EOG 300 pg67-71 Electrical System Response - Tulsa