Agricultural Overhead Power Line Safety Poster – Contact with overhead power lines is the leading cause of electrical fatalities for agricultural workers. Of the 1,001 reported power line contact incidents from 2003-2009, nearly 70% resulted in death. Luckily, these fatalities can be prevented by following these simple steps while on the job.

1. Locate all overhead power lines
2. Keep self and equipment 10 feet away from all overhead power lines
3. Do not touch anything that is in contact with the power line
4. Beware of fencing near power lines
5. Carry ladders and other equipment horizontally
6. Lower equipment apparatus before driving
7. Never spray near power lines with irrigation systems
8. Stay at least 35 feet away from fallen power lines

When working with overhead power lines what is a suitable precaution to take?

What you need to know – Accidental contact with live overhead power lines kills people and causes many serious injuries every year. People are also harmed when a person or object gets too close to a line and a flashover occurs. Work involving high vehicles or long equipment is particularly high risk, such as; In Construction – Lorry mounted cranes (such as Hiabs or Palingers), Mobile Elevated Work Platforms (MEWP’s), scaffold poles, tipper vehicles, cranes, ladders; In Agriculture – combines, sprayer booms, materials handlers, tipper vehicles, ladders, irrigation pipes, polytunnels; Remember:

going close to a live overhead line can result in a flashover that may kill. Touching a power line is not necessary for danger; voltages lower than 230 volts can kill and injure people; do not mistake overhead power lines on wooden poles for telephone wires; and electricity can bypass wood, plastic or rubber, if it is damp or dirty, and cause fatal shocks. Don’t rely on gloves or rubber boots to protect you.

The guidance note ” Avoiding danger from overhead power lines ” describes how to work safely near overhead power lines in a range of industries. The Electricity Networks Association (ENA) publications:

Safety Information for Farmers and Agricultural Contractors Watch It! In the Vicinity of Overhead Lines Safety Information for Farmers Utilising Polytunnels Safe tree working in proximity to overhead electric lines ENA Engineering Recommendation G55/1 The ENA also provide advice on what to do if machinery comes into contact with an overhead power line.

What is the risk for working on overhead power lines?

DANGER – OVERHEAD POWER LINES Working within 10 feet of overhead power lines increases the risk of electrical shock from accidental contact with these lines. Workers are exposed to the risk of death by electrocution or serious and disabling injuries.

What is safety factor in overhead line?

Free SSC JE: General Intelligence & Reasoning Free Mock Test 20 Questions 20 Marks 12 Mins The load permissible stresses on the structural members, conductors and ground wire of self supporting steel lattice towers for overhead transmission lines shall be in accordance with the specifications laid down, from time to time, by the Bureau of Indian Standards.

for metal supports – 1.5 for mechanically processed concrete supports – 2.0 for hand moulded concrete supports – 2.5 for wood supports – 3.0

Minimum factors of safety:

The minimum factors of safety shall be based on such load as may cause failure of the supports to perform its function. The load shall be equivalent to the yield point stress or the modulus of rupture, as the case may be, for sup­ports subject to bending and vertical loads, and the crippling load for supports used struts. The strength of the sup­ports of the overhead lines in the direction of the line shall not less than one-fourth of the strength required in the direction transverse to the line. The minimum factor of safety for stay wires, guard wires or bearer wires shall be 2.5 based on the ultimate tensile strength of the wire. The minimum factor of safety for conductors shall be 2, based on their ultimate tensile strength.

Last updated on Jul 27, 2023 SSC JE EE Notification 2023 has been released on 26th July 2023. A total of 198 vacancies have been announced in various departments of the Central Government. The last date to apply online is 16th August 2023 Candidates with a degree/diploma in the relevant engineering stream are eligible for this post.

1. The selection will be based on Computer Based Test (Paper I, Paper-II), Document Verification, and Medical Examination.
2. Physical Standard Test/Physical Efficiency Test is conducted only for candidates applying in BRO.
3. The finally appointed candidates will get a salary range between Rs.35,400/- to Rs.1,12,400/-.

To get a successful selection candidates can refer to the SSC JE EE previous year’s papers to estimate the level of the exam.

Are overhead power lines a health risk?

Studies on electric fields – Studies investigating the effects of electric fields have suggested that small charged particles, known as corona ions, which are generated by power lines, may cause health effects. However, there is little evidence to support this possibility.

What PPE is required for high voltage lines?

PPEs Required to Enter a Substation – PPE is a key part of safety precautions in substations, Most utilities and industrial firms spell out PPE requirements, usage and maintenance instructions as a part of their safety protocol. Employers must make sure the PPEs available on site include:

Hard hats (with full/partial brims as necessary) Safety glasses with side shields Face shields and masks Suitable footwear (safety/steel-toed boots, rated dielectric footwear) Insulating gloves (rated, used along with leather/cloth linings for shock protection) Insulated tools Electrical/insulation blankets Live-line tools/hot sticks

Batteries and other chemicals that find use in substations pose a chemical hazard in the environment, which may require the use of respirators and other chemically resistant PPEs, clothing, gloves and footwear to safeguard personnel. Special safety equipment designed for use in confined/cramped spaces, barricades, scaffolding, gas/smoke detectors must also be available on demand.

What is the safe clearance from overhead power lines?

Always maintain a distance of at least 10 feet from overhead lines and more than 10 feet if the voltage to ground is over 50 kilovolts (50,000 volts). The higher the voltage, the greater the distance that is needed between the lines and the workers.

What materials should be avoided when working near power lines?

Conclusion – Metal ladders = electrocution. To avoid serious injury or death, workers using ladders should always assume nearby powerlines and overhead wires are live and energized. Metal ladders—and even wooden or fiberglass ladders with metal components—should never be used in these scenarios.

What are the best practices with power lines?

Stay at least 10 feet away from overhead power lines and assume they are energized. De-energize and ground lines when working near them. Use non-conductive wood or fiberglass ladders when working near power lines. Worn cords can expose the wires within, or loosen the connections on the plug end.

What are common faults in overhead power lines?

Overhead Lines Protection – Faults and Protection Devices The most common causes of faults in overhead lines are:

• Aircraft and cars hitting lines and structures
• Birds and animals
• Contaminated insulators
• Ice and snow loading
• Lightning
• Partial discharges () not controlled
• Punctured or broken insulators
• Trees
• Wind

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What are the risks associated with power lines?

Are there other health risks associated with electromagnetic fields? – Exposure to low-level electromagnetic fields has been studied extensively, and there is no evidence that it is harmful to human health, according to the World Health Organization,

In fact, according to the WHO website, most scientists and doctors agree that if there are any health effects from low-level electromagnetic fields, they are likely to be very small compared to other health risks that people face in daily life. Other agencies, like the European Commission Scientific Committee on Emerging and Newly Identifiable Health Risks, take a more cautious stance.

They say that it’s possible, but far from conclusive, that extremely low-frequency magnetic fields could be carcinogenic, or have the potential to cause cancer, in a 2015 report.

What are the 5 components of overhead lines?

Senior Electrical Power System Engineer | Power Systems Expert – Published Jun 16, 2018 An overhead line consists of conductors and ground wires, towers, insulation, hardware, and foundations. The transmission line conductors are specialized, with large cross section and relatively few strands.

1. Normal AC power lines use phase conductors with a central core of a few steel wires, surrounded by a sheath of many more aluminum wires wound in helixes of alternating direction.
2. Power line conductors seem rigid when a 1-m length is handled, but over a 300-m span length, they are flexible enough to sag in a catenary between attachment points, following Bernoulli’s law.

The sag of the conductor varies considerably with its tension, age, loading history, and temperature. It is always impressive to witness a modern overhead line conductor stringing operation. As illustrated in Fig.1, a helicopter pulls a pilot rope through a series of pulleys or travelers, attached to insulator strings.

• The rope is attached to a wire and pulled through the travelers using a large winch at ground level.
• The wire is attached to a conductor sling that can support the full pulling tension force.
• After the complete conductor has been pulled into travelers on several spans, it is allowed to set for a specified time, during which a permanent deformation called creep takes place.

The creep relaxes the line tension and increases the sag. After some hours or days of creep, the slack is pulled out and the conductor is ready to be fixed in the insulator strings. FIGURE 1 Helicopter stringing of 230-kV double circuit lattice tower transmission line. Conductors are hung in stringing sections consisting of several suspension points between dead-end towers, The dead-end or strain towers have high ratings for mechanical loads along the line direction.

Insulators at dead-end structures are normally horizontal and loaded only in tension. High-voltage conductors are normally hung from a tower above using I-string suspension insulators, also in tension. The suspension insulators are free to swing along the line direction, which tends to equalize the tensions in all spans.

A double chain of insulators, forming a V ( V-string ) or parallel columns ( double I string ) can restrain the lateral movement of the conductor, rather than allowing the conductor to move sideways to its blowout angle under side-wind conditions. At some transmission voltage levels, the improved visual appearance of horizontal or vertical post insulators is desirable.

These insulators also restrain the motion of the conductor, leading to compact designs. There are a wide variety of transmission tower designs, all beautiful to the engineers that designed them but not so pleasing to entire communities. Steel construction is most common, and galvanized steel lattice towers engineered with slide rule calculations in the early 1900s still meet wind and ice loads today.

In urban areas, slender steel pole structures are heavier and more costly but present a modern appearance as shown in Fig.2. FIGURE 2 Steel pole double circuit transmission lines in urban corridor. Electrical clearances at low points on the span, or high points on the ground profile, are established using a combination of physical buffers (e.g., legal vehicle height) and electrical buffers, which increase as a function of system voltage.

The heights of the conductors at towers are established by the anticipated sag of the conductor between attachment points, considering the highest operating temperature of the line as well as the long-term effects of creep in the aluminum layers. Design of transmission tower foundations, considering vertical uplift and side loads as well as compression, is the domain of the civil engineer, supported by soil specialists and geotechnical surveys of the planned right-of-way.

The foundations at tower base may be supplemented with guy wires, terminated in rock or soil anchors. These metal electrodes in the soil also transfer currents from power system faults and lightning flashes to remote earth. The potential rise under fault conditions presents some risk of electric shock that is mitigated with the use of high-speed fault detection to reduce the duration of exposure.

What would happen if you touched a power line?

Misconception #2: Power lines are insulated, so they’re safe to touch. – This is a common misconception that many people have about power lines. Power lines are not insulated and you should always avoid contact with them. It is quite possible for people to get electrocuted if you touch power lines.

What is the minimum safe distance from power lines?

What is the minimum safe working distance from electrical apparatus in NSW? – There are specific guidelines to follow when performing work in the vicinity of power lines or other charged electrical apparatus. This is known as the minimum clearance distance or the minimum safe working distance.

Up to and including 132,000 volts: 3 metres 132,000 volts to 330,000 volts: 6 metres Over 330,000 volts: 8 metres

This applies to all electrical apparatus and equipment, including overhead power lines (also known as high-voltage lines). Regardless of whether you operate a crane for electrical workers or you drive a tipper truck on a worksite. Where high-voltage lines are present, you cannot work within these distances unless you are accredited to do so.

What is the common safety factor?

Safety factor calculation – Safety factor is calculated by dividing the ultimate load capacity of a structure by the design load. Ultimate load capacity is the maximum load that a structure can withstand before failure. Design load is the expected load that a structure will experience during its service life.

1. Safety factor is usually expressed as a ratio or a percentage.
2. For example, a safety factor of 2 means that the structure can resist twice as much load as it is designed for, or that it has a 100% margin of safety.
3. A typical safety factor range is between 1.2 and 4, depending on the type of structure and load.

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What is a good safety factor?

General Recommendations

What is minimum safety factor?

What’s the big picture when it comes to Factor of Safety (FoS)? – “Factor of Safety” usually refers to one of two things: 1) the actual load-bearing capacity of a structure or component, or 2) the required margin of safety for a structure or component according to code, law, or design requirements. A very basic equation to calculate FoS is to divide the ultimate (or maximum) stress by the typical (or working) stress. A FoS of 1 means that a structure or component will fail exactly when it reaches the design load, and cannot support any additional load. Structures or components with FoS < 1 are not viable; basically, 1 is the minimum. With the equation above, an FoS of 2 means that a component will fail at twice the design load, and so on. Different industries have different ideas on what a required margin of safety should be ; one of the difficulties associated with using a FoS or SF is some measure of ambiguity. But there are some general rules of thumb across multiple verticals. Obviously, if the consequences of failure are significant, such as loss of life, personal harm, or property loss, a higher FoS will be required by design or by law. Another consideration is cost: how much extra does it cost per part to achieve a certain FoS, and is that a viable business model?

Can overhead power lines cause headaches?

Results (acc. to author) – 15 out of 132 participants of the exposed group reported recurrent headache or migraine, compared with 1 of 94 in the control group,10 participants reporting recurrent headache lived in houses in a distance of 60-80 m to the power line,

What are the symptoms of EMF exposure?

What is EHS? – EHS is characterized by a variety of non-specific symptoms, which afflicted individuals attribute to exposure to EMF. The symptoms most commonly experienced include dermatological symptoms (redness, tingling, and burning sensations) as well as neurasthenic and vegetative symptoms (fatigue, tiredness, concentration difficulties, dizziness, nausea, heart palpitation, and digestive disturbances).

• The collection of symptoms is not part of any recognized syndrome.
• EHS resembles multiple chemical sensitivities (MCS), another disorder associated with low-level environmental exposures to chemicals.
• Both EHS and MCS are characterized by a range of non-specific symptoms that lack apparent toxicological or physiological basis or independent verification.

A more general term for sensitivity to environmental factors is Idiopathic Environmental Intolerance (IEI), which originated from a workshop convened by the International Program on Chemical Safety (IPCS) of the WHO in 1996 in Berlin. IEI is a descriptor without any implication of chemical etiology, immunological sensitivity or EMF susceptibility.

What are the safety precautions of line tester?

Safety Precaution while working –

Follow the proper electrical guide lines and take careCarry out electrical jobs under electrical supervisor.Never touch the open wire/Conductor even if the tester shows absence of phase or hot supply.Use Line Tester only for the supply voltage ranging from 100V-500V.Don’t use Phase or Line Tester with High voltages because it may cause electrocution.Handle the Line tester with care. Neon bulb or element may damage.The licensed electricians must work on electricity. It may be dangerous if the person does not have competency on working on electrical supply system.Electricity is very dangerous. Therefore, read all caution and instruction while doing electrical work.Keep concentration while working on electrical equipment & electrical system.

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What is the safe clearance from overhead power lines?

Always maintain a distance of at least 10 feet from overhead lines and more than 10 feet if the voltage to ground is over 50 kilovolts (50,000 volts). The higher the voltage, the greater the distance that is needed between the lines and the workers.

What is the precaution of transmission line?

Understanding Transmission – How You Get Your Electricity » –

Maintain a safe distance from transmission wires irrespective of possible de-energization as they are bare, and uninsulated. Do not touch, climb, or tamper with substation fencing. The protective barrier is for your safety. Stay clear of any electrical facilities. Climbing structures or related activities could result in injury and equipment failure. Never attempt to steal copper or any other material from a substation. Copper is a conductor that is used to deliver electricity. Stealing copper may steal your life. Never climb a transmission tower and avoid contacting other high voltage electrical equipment or power lines. Vandalism of high voltage electrical facilities and structures can lead to serious injury or death. Removal of equipment from substations, communication sites, or power line facilities can impact the grid and unsafe operations. Intentional damage of transmission facilities or associated property can result in prosecution under applicable state and federal laws.

What are the 5 components of overhead lines?

Senior Electrical Power System Engineer | Power Systems Expert – Published Jun 16, 2018 An overhead line consists of conductors and ground wires, towers, insulation, hardware, and foundations. The transmission line conductors are specialized, with large cross section and relatively few strands.

1. Normal AC power lines use phase conductors with a central core of a few steel wires, surrounded by a sheath of many more aluminum wires wound in helixes of alternating direction.
2. Power line conductors seem rigid when a 1-m length is handled, but over a 300-m span length, they are flexible enough to sag in a catenary between attachment points, following Bernoulli’s law.

The sag of the conductor varies considerably with its tension, age, loading history, and temperature. It is always impressive to witness a modern overhead line conductor stringing operation. As illustrated in Fig.1, a helicopter pulls a pilot rope through a series of pulleys or travelers, attached to insulator strings.

1. The rope is attached to a wire and pulled through the travelers using a large winch at ground level.
2. The wire is attached to a conductor sling that can support the full pulling tension force.
3. After the complete conductor has been pulled into travelers on several spans, it is allowed to set for a specified time, during which a permanent deformation called creep takes place.

The creep relaxes the line tension and increases the sag. After some hours or days of creep, the slack is pulled out and the conductor is ready to be fixed in the insulator strings. FIGURE 1 Helicopter stringing of 230-kV double circuit lattice tower transmission line. Conductors are hung in stringing sections consisting of several suspension points between dead-end towers, The dead-end or strain towers have high ratings for mechanical loads along the line direction.

• Insulators at dead-end structures are normally horizontal and loaded only in tension.
• High-voltage conductors are normally hung from a tower above using I-string suspension insulators, also in tension.
• The suspension insulators are free to swing along the line direction, which tends to equalize the tensions in all spans.

A double chain of insulators, forming a V ( V-string ) or parallel columns ( double I string ) can restrain the lateral movement of the conductor, rather than allowing the conductor to move sideways to its blowout angle under side-wind conditions. At some transmission voltage levels, the improved visual appearance of horizontal or vertical post insulators is desirable.

These insulators also restrain the motion of the conductor, leading to compact designs. There are a wide variety of transmission tower designs, all beautiful to the engineers that designed them but not so pleasing to entire communities. Steel construction is most common, and galvanized steel lattice towers engineered with slide rule calculations in the early 1900s still meet wind and ice loads today.

In urban areas, slender steel pole structures are heavier and more costly but present a modern appearance as shown in Fig.2. FIGURE 2 Steel pole double circuit transmission lines in urban corridor. Electrical clearances at low points on the span, or high points on the ground profile, are established using a combination of physical buffers (e.g., legal vehicle height) and electrical buffers, which increase as a function of system voltage.

The heights of the conductors at towers are established by the anticipated sag of the conductor between attachment points, considering the highest operating temperature of the line as well as the long-term effects of creep in the aluminum layers. Design of transmission tower foundations, considering vertical uplift and side loads as well as compression, is the domain of the civil engineer, supported by soil specialists and geotechnical surveys of the planned right-of-way.

The foundations at tower base may be supplemented with guy wires, terminated in rock or soil anchors. These metal electrodes in the soil also transfer currents from power system faults and lightning flashes to remote earth. The potential rise under fault conditions presents some risk of electric shock that is mitigated with the use of high-speed fault detection to reduce the duration of exposure.

Jack Gloop