1. Always Disconnect – The first rule of electrical safety is to always disconnect whatever you’re working on. This might mean unplugging an appliance that requires repairs or turning off a circuit breaker. You must disconnect before performing any electrical work to reduce the risk of electrocution.
Contents
What is the golden rule of electrical safety?
Disconnect and Turn it Off – The first rule of electrical safety is to always disconnect an appliance or anything else that’s powered by electricity before performing any repairs. If electricity is flowing, there’s a risk of electrocution, no matter how safe you are.
What is the single most important aspect of electrical safety?
The single most important aspect of electrical measurement safety is following NFPA 70E. Work de-energized whenever possible.
What is the most important element of safety?
Management Leadership and Employee Involvement – Communication is perhaps the most important element of workplace safety. This means communication and involvement between the employer and the employee in relation to workplace safety and health issues. Such communication would include:
A copy of the company’s employee safety and health policy being posted clearly Encouragement of employee involvement in policy-making for health and safety issues Employee participation in safety activities and communicating understanding & questions
among many others. A general rule of thumb for communication with regard to workplace safety is that it is always preferable to over-communicate than to come up short or leave room for miscommunication. In our experience as leading Ontario workplace safety experts, we have seen countless instances where better workplace communication could have prevented an incident from happening or mitigated the chances of occurrence.
What is the importance of basic electrical safety?
Why Electrical Safety Is Important – Electrical safety matters because electricity is powerful and potentially harmful. Mishandled electricity can cause serious injury or death, so keeping electricians safe at work requires use of the proper techniques.
Exercise caution: Always use caution when working with electrical gear. Assume that you’re working with live, energized wires and act accordingly. Check for electrical current: Before touching a wire or metal surface, use a multimeter to see if it has an electrical current. Secure electrical cords: Tape extension cords around the work site to the floor or wall — hanging cords can fall and hurt someone, and laying them loosely can be a tripping hazard. Be mindful of conductive materials: Know which materials are conductive and don’t use them around high-voltage equipment. Inspect cords and electrical connections: Regularly examine cords and connections like outlets and plugs for signs of wear and damage. If you find issues, replace the component immediately. Wear personal protective equipment (PPE): Wear PPE like safety glasses, insulated gloves and a hard hat when using electrical items.
What voltage is safe to touch?
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The human hazard of electric current depends on the intensity and duration of current flow in a specific current path through the body. The technical specification IEC TS 60479-1 comprises the permissible touch currents and the required data to calculate the permissible touch voltages under several conditions (e.g., body resistance, current path, skin moisture (see Parameters for effects of electric current ) for alternating current and direct current, A touch voltage of 50 V AC (1-1000 Hz ) or 120 V DC for long shock duration (> 3 s) should not be exceeded in healthy adults otherwise a life-threatening condition may occur. For children and livestock the touch voltage is limited to 25 V AC or 60 V DC, In workplaces, higher short-term touch voltages above 50 V AC or 120 V DC are permissible for tasks at energized parts under certain conditions. Only specially trained employees are allowed to carry out the tasks using personal protective equipment and specific safety protection measurements. Following specifications are valid for example:
- IEC 60364-4-41:2005. Low-voltage electrical installations – Part 4-41: Protection for safety – Protection against electric shock
- EN 50110-1 ed.3: 2013. Operation of electrical installations – Part 1: General requirements
- EN 50122-1 ed.2: 2015. Railway applications – Fixed installations – Electrical safety, earthing and the return circuit – Part 1: Protective provisions against electric shock
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What are electrical rules?
Introduction Indian Electricity Rules, 1956 was made under Section 37 of the Indian Electricity Act, 1910. It has been redefined after the enactment of Electricity Act, 2003. The provisions cover safety aspects, licensing provisions, appointment of inspectors etc.
- Indian Electricity Rules, 1956 get repealed with the notification of Regulation and Measures relating to Safety and Electric Supply under Section 185 (2) (c) of Electricity Act, 2003.
- Applicability It is applicable on the States for which Central Electricity Board has made these Rules under Section 37 of Electricity Act, 1910, to regulate the generation, transmission, supply and use of energy, and to carry out the purposes and objects of Electricity Act, 1910.
Chapter IX shall apply only where energy is used for purposes of traction and Chapter X shall apply only where energy is used in mines as defined in the Mines Act, 1952. Frequently Asked Questions (FAQs) What are the requirements for Preparations and submission of accounts under Indian Electricity Rules, 1956? Every licensee shall prepare and render his accounts (to be made up to 31 st day of March each year) as well as an annual statement in accordance with the provisions of Electricity Act.
All supply lines and apparatus to be of sufficient power ratings and to be insulated properly to ensure safety of humans and animals. Supplier to ensure safety of wires and apparatus at consumer’s premises. Switches to be there on live conductor. No cut out to be inserted in the neutral conductor While marking conductors, code of practice of wiring to be followed. Energy not be supplied as per Rule 50 unless the following are observed: Danger notice to be affixed permanently in conspicuous places. Adequate precautions before handling an electric supply line or apparatus. Instructions for restoration of persons suffering from electric shock to be placed in conspicuous places. Intimation of an accident to be notified to the Inspector within 24 hours from the time of occurrence.
What are the General conditions relating to supply and use of energy under Indian Electricity Rules, 1956?
Testing of consumer’s installation before additional supply or reconnection. To take necessary precautions against leakage before connection. If supplier has reason to believe there seems to be a leakage in the consumer’s system, he must give the consumer reasonable notice for inspection. Energy not to be supplied, transformed, converted, or used unless the below conditions are fulfilled:
A linked switch which is suitable, or a circuit breaker is to be erected at, the secondary side of the transformer. All circuits have to be protected by a suitable cut-out. Supply to each motor or group of motors is controlled by a linked switch or circuit breaker. Adequate precautions are taken to ensure that no live parts are exposed.
Additional provisions applicable to buildings more than 15 meters in height.30 days’ notice in writing along with particulars to be given to the inspector. There should not be any variation from declared voltage of supply to consumer. Precautions against failure of supply to be taken.
What are the requirements for Electric Supply Lines, Systems and Apparatus for Low and Medium Voltages under Indian Electricity Rules, 1956?
Installation of earth leakage protective device so as to disconnect the supply instantly on the occurrence of earth fault or leakage of current. Test for resistance of insulation (Rule 48) to be conducted before reconnecting a disconnected system.
What are the requirements for Electric Supply Lines, Systems and Apparatus for High and Extra-High voltages under Indian Electricity Rules, 1956?
Approval of Inspector necessary condition before energizing any high voltage installations. Apparatus and equipment intended to be used at high or extra high voltage shall be inaccessible except for authorized person. Suitable segregation to be provided for licensee’s equipment. Soak pit or alternate system to drain out the oil shall be made in sub-stations where the transformers are provided. Cable trench shall be fitted with sand or other non-flammable material and covered by bricks. The installation must be subjected to the prescribed testing before energizing. Conductors to be enclosed in a metallic covering and suitable circuit breakers to be provided to protect the equipment from overloading. In the case of outdoor type of sub-station, a metallic fencing of not less than 1.8 m height shall be erected around the transformer.
What are the compliances for Overhead Lines, Under Ground Cables and Generating Stations under Indian Electricity Rules, 1956?
Overhead line conductors to have a material strength of not less than 350 kg. In case of low voltage, a conductor of not less than 150 kg may be used. Maximum stress, ground clearance and other clearances to be as per the standards laid down in the rules. Overhead lines shall not be erected in the vicinity of aerodromes until the aerodrome authorities have approved in writing the route of the proposed lines. Guarding and Earthing as per the standards laid down in the rules. Safety and protective devices as specified in the rules. Ensure protection against lightning.
What are the compliances for Electric Traction under Indian Electricity Rules, 1956?
It is not applicable to energy used for the public carriage of passengers, animals or goods on, or for the lighting or ventilation of the rolling stock of any railway or tramway subject to the provisions of the Indian Railways Act, 1890 Every line to be insulated Passengers should not have access to electrical circuit. Earthing of guard wires to be done. Records as prescribed in the Rules to be maintained.
What are the additional precautions to be adopted in mines and oil-fields under Indian Electricity Rules, 1956?
The responsibility for observance of rules lies with owner, agent, engineer or manager of a mine, or of the agent, engineer of any company operating in an oil field and it shall be duty of all persons employed to conduct their work in accordance with the rules. Notice to be sent to Inspector on 1 st February of every year in respect of every mine or oil field. A plan showing the position of all fixed apparatus and conductors to be kept by the manager or owner as well as the licensee. Precautions against lightning and fire to be taken and ensure efficient means of communication to be provided in every mine. Transformers and switchgears to be placed in isolation to avoid danger. Earthing and voltage limits as prescribed in the rules. Properly constructed switchgear for disconnecting the supply of energy to a mine or oilfield shall be provided at a point approved by the Inspector. All apparatus to be kept free from dust and moisture. Appropriate precautions to be taken in case of existence of gas. Earthing of neutral points i.e. if the voltage of an alternating current system exceeds 30 volts, the neutral or mid-point shall be earthed.
What is the Government’s and Inspector’s Power to make relaxations to the Rules? The State, Central Governments and Inspector has the power to make relaxations to certain provisions of the Rules as mentioned in Rule 133 and 134 respectively. Every relaxation by Inspector shall be reported forthwith to, and shall be disallowed or revised by, the State Government, or where the relaxation affects mines, oil-fields or railways, by the Central Government.
What are the five electrical fundamentals?
Electrical Fundamentals — Basic Electric Circuit Theory A little bit of history is in order before we get into AC and DC circuit theory. In the latter part of the 19 th century there were three principal players in the electrical generation and transmission industry.
- Thomas Edison, known as the “Wizard of Menlo Park” and most famous for his invention of the electric light bulb, was the main proponent of direct current (DC) transmission.
- George Westinghouse and Nikola Tesla were the main proponents of alternating current (AC) transmission.
- History documents this formative period in the development of electrical generation and transmission as the “War of Currents.” Edison has been portrayed as the tireless inventor filing more than 1000 patent applications with the U.S.
Patent Office. Since he was more of an inventor than a mathematician or physicist, he was not very receptive to the analytical complexities of alternating current. Tesla was quite the opposite in that he developed many theories concerning single-phase and polyphase systems.
Westinghouse was an inventor like Edison, but he was also an engineer. He provided the financial backing for the development of a working AC network. It is noted in the literature that Edison went to great lengths to discredit AC power and its unsafe nature. He carried out many public relations campaigns by electrocuting animals with AC power.
In the end, Westinghouse’s development of the transformer allowed alternating current to be the correct choice for power generation and transmission. Figure 1. DC Waveform Every time you start your vehicle, run a cordless drill, or use any type of electronic equipment you are using DC. The battery in your vehicle uses chemical energy to separate positive and negative charge thereby developing a potential difference between its terminals to produce 12 VDC to crank the engine.
The battery in your cordless drill uses a similar mechanism to power the drill’s motor. The electronic equipment you use every day, excluding portable equipment, converts the incoming AC supply to DC through a process known as rectification. Figure 1 is an example of a constant DC waveform. The lights in your office, the receptacles you plug devices in within your home, and the large motors in a manufacturing facility are examples of equipment that use AC.
AC power is generated and distributed in the United States at a frequency of 60 Hertz. The AC waveform is time varying and uses a sinusoidal function to model its behavior. Figure 2 illustrates a sinusoidal AC waveform. There are five electrical properties that have to be introduced in circuit theory to help with the analysis. Figure 2. AC Waveform Resistance (R) can be defined as the property of a material to oppose movement of charge or current flow. The unit of resistance is the ohm. Resistors are components that oppose current flow. Figure 4 illustrates a circuit with resistors in series and a circuit with resistors in parallel.
- It is important to note that in a series circuit the current is the same through each element, and in a parallel circuit the voltage is the same across each element.
- Capacitance (C) can be defined as the property of a material to oppose any change in voltage across the material.
- The unit of capacitance is the farad.
Capacitance occurs when two conducting materials are separated by an insulator. In a parallel plate capacitor two conducting plates are separated by an insulator known as a dielectric. The capacitor has the ability to block DC signals and pass AC signals.
- Under steady state conditions the capacitor acts like an open circuit to DC and a frequency selective device to AC.
- Figure 5 illustrates a circuit with capacitors in series and a circuit with capacitors in parallel.
- Inductance (L) can be defined as the property of a material to oppose any change in current through the material.
The unit of inductance is the henry. All conductors even those not coiled have some inductance. Under steady state conditions the inductor acts like a short circuit to DC and a frequency selective device to AC. Figure 6 illustrates a circuit with inductors in series and a circuit with inductors in parallel with no mutual coupling. Figure 3. Electrical Components Reactance or more specifically capacitive reactance (Xc) and inductive reactance (Xl) can be defined as the opposition to current flow these components present under AC conditions. The unit of reactance is the ohm. These devices change their reactance based on the applied frequency. Figure 4. Resistor Circuits Useful Theorems. We have already mentioned Ohm’s Law. Two other very useful network theorems are Kirchhoff’s Voltage Law (KVL) and Kirchhoff’s Current Law (KCL). KVL states that in the closed loop of a circuit, also called a mesh, the algebraic sum of the voltage drops and voltage rises equals zero.
The Superposition Theorem Thevenin’s Theorem Norton’s Theorem The Maximum Power Transfer Theorem Delta/Wye – Wye/Delta Conversion Theorem
Figure 5. Capacitor Circuits The Superposition Theorem allows you to solve complex networks with multiple voltage sources. Thevenin’s Theorem allows you to convert a complex network into a simple circuit with a Thevenin’s equivalent voltage source and a Thevenin’s equivalent series resistor.
Norton’s Theorem allows you to convert a complex network into a simple circuit with a Norton’s equivalent current source and a Norton’s equivalent parallel resistor. These three network theorems are very useful in electronics applications. The Maximum Power Transfer Theorem states maximum power is transferred from the source to the load when the internal resistance of the load matches the internal resistance of the source.
This theorem is very useful in power and communications applications. The Delta/Wye – Wye/Delta Conversion Theorem allows you to convert back and forth between a Delta-connected network and a Wye-connected network. This theorem is very useful in power and electronics applications. Figure 6. Inductor Circuits : Electrical Fundamentals — Basic Electric Circuit Theory
What is the first rule of electrical safety?
1. Always Disconnect – The first rule of electrical safety is to always disconnect whatever you’re working on. This might mean unplugging an appliance that requires repairs or turning off a circuit breaker. You must disconnect before performing any electrical work to reduce the risk of electrocution.
What are electrical rules?
Introduction Indian Electricity Rules, 1956 was made under Section 37 of the Indian Electricity Act, 1910. It has been redefined after the enactment of Electricity Act, 2003. The provisions cover safety aspects, licensing provisions, appointment of inspectors etc.
Indian Electricity Rules, 1956 get repealed with the notification of Regulation and Measures relating to Safety and Electric Supply under Section 185 (2) (c) of Electricity Act, 2003. Applicability It is applicable on the States for which Central Electricity Board has made these Rules under Section 37 of Electricity Act, 1910, to regulate the generation, transmission, supply and use of energy, and to carry out the purposes and objects of Electricity Act, 1910.
Chapter IX shall apply only where energy is used for purposes of traction and Chapter X shall apply only where energy is used in mines as defined in the Mines Act, 1952. Frequently Asked Questions (FAQs) What are the requirements for Preparations and submission of accounts under Indian Electricity Rules, 1956? Every licensee shall prepare and render his accounts (to be made up to 31 st day of March each year) as well as an annual statement in accordance with the provisions of Electricity Act.
All supply lines and apparatus to be of sufficient power ratings and to be insulated properly to ensure safety of humans and animals. Supplier to ensure safety of wires and apparatus at consumer’s premises. Switches to be there on live conductor. No cut out to be inserted in the neutral conductor While marking conductors, code of practice of wiring to be followed. Energy not be supplied as per Rule 50 unless the following are observed: Danger notice to be affixed permanently in conspicuous places. Adequate precautions before handling an electric supply line or apparatus. Instructions for restoration of persons suffering from electric shock to be placed in conspicuous places. Intimation of an accident to be notified to the Inspector within 24 hours from the time of occurrence.
What are the General conditions relating to supply and use of energy under Indian Electricity Rules, 1956?
Testing of consumer’s installation before additional supply or reconnection. To take necessary precautions against leakage before connection. If supplier has reason to believe there seems to be a leakage in the consumer’s system, he must give the consumer reasonable notice for inspection. Energy not to be supplied, transformed, converted, or used unless the below conditions are fulfilled:
A linked switch which is suitable, or a circuit breaker is to be erected at, the secondary side of the transformer. All circuits have to be protected by a suitable cut-out. Supply to each motor or group of motors is controlled by a linked switch or circuit breaker. Adequate precautions are taken to ensure that no live parts are exposed.
Additional provisions applicable to buildings more than 15 meters in height.30 days’ notice in writing along with particulars to be given to the inspector. There should not be any variation from declared voltage of supply to consumer. Precautions against failure of supply to be taken.
What are the requirements for Electric Supply Lines, Systems and Apparatus for Low and Medium Voltages under Indian Electricity Rules, 1956?
Installation of earth leakage protective device so as to disconnect the supply instantly on the occurrence of earth fault or leakage of current. Test for resistance of insulation (Rule 48) to be conducted before reconnecting a disconnected system.
What are the requirements for Electric Supply Lines, Systems and Apparatus for High and Extra-High voltages under Indian Electricity Rules, 1956?
Approval of Inspector necessary condition before energizing any high voltage installations. Apparatus and equipment intended to be used at high or extra high voltage shall be inaccessible except for authorized person. Suitable segregation to be provided for licensee’s equipment. Soak pit or alternate system to drain out the oil shall be made in sub-stations where the transformers are provided. Cable trench shall be fitted with sand or other non-flammable material and covered by bricks. The installation must be subjected to the prescribed testing before energizing. Conductors to be enclosed in a metallic covering and suitable circuit breakers to be provided to protect the equipment from overloading. In the case of outdoor type of sub-station, a metallic fencing of not less than 1.8 m height shall be erected around the transformer.
What are the compliances for Overhead Lines, Under Ground Cables and Generating Stations under Indian Electricity Rules, 1956?
Overhead line conductors to have a material strength of not less than 350 kg. In case of low voltage, a conductor of not less than 150 kg may be used. Maximum stress, ground clearance and other clearances to be as per the standards laid down in the rules. Overhead lines shall not be erected in the vicinity of aerodromes until the aerodrome authorities have approved in writing the route of the proposed lines. Guarding and Earthing as per the standards laid down in the rules. Safety and protective devices as specified in the rules. Ensure protection against lightning.
What are the compliances for Electric Traction under Indian Electricity Rules, 1956?
It is not applicable to energy used for the public carriage of passengers, animals or goods on, or for the lighting or ventilation of the rolling stock of any railway or tramway subject to the provisions of the Indian Railways Act, 1890 Every line to be insulated Passengers should not have access to electrical circuit. Earthing of guard wires to be done. Records as prescribed in the Rules to be maintained.
What are the additional precautions to be adopted in mines and oil-fields under Indian Electricity Rules, 1956?
The responsibility for observance of rules lies with owner, agent, engineer or manager of a mine, or of the agent, engineer of any company operating in an oil field and it shall be duty of all persons employed to conduct their work in accordance with the rules. Notice to be sent to Inspector on 1 st February of every year in respect of every mine or oil field. A plan showing the position of all fixed apparatus and conductors to be kept by the manager or owner as well as the licensee. Precautions against lightning and fire to be taken and ensure efficient means of communication to be provided in every mine. Transformers and switchgears to be placed in isolation to avoid danger. Earthing and voltage limits as prescribed in the rules. Properly constructed switchgear for disconnecting the supply of energy to a mine or oilfield shall be provided at a point approved by the Inspector. All apparatus to be kept free from dust and moisture. Appropriate precautions to be taken in case of existence of gas. Earthing of neutral points i.e. if the voltage of an alternating current system exceeds 30 volts, the neutral or mid-point shall be earthed.
What is the Government’s and Inspector’s Power to make relaxations to the Rules? The State, Central Governments and Inspector has the power to make relaxations to certain provisions of the Rules as mentioned in Rule 133 and 134 respectively. Every relaxation by Inspector shall be reported forthwith to, and shall be disallowed or revised by, the State Government, or where the relaxation affects mines, oil-fields or railways, by the Central Government.
What is the law of electrical principle?
The video about conductance, resistance, and ohm’s law – Ohm’s law states that the current through a conductor between two points is directly proportional to the voltage across the two points. Ohm’s law is used to validate the static values of circuit components such as current levels, voltage supplies, and voltage drops.
No. Ohm’s law is not a universal law. This is because Ohm’s law is only applicable to ohmic conductors such as iron and copper but is not applicable to non-ohmic conductors such as semiconductors. Ohm’s law doesn’t apply to semiconducting devices because they are nonlinear devices. This means that the ratio of voltage to current doesn’t remain constant for variations in voltage.
Ohm’s law fails to explain the behaviour of semiconductors and unilateral devices such as diodes. Ohm’s law may not give the desired results if the physical conditions such as temperature or pressure are not kept constant. Stay tuned to BYJU’S and Fall in Love with Learning ! : Ohm’s Law – Statement, Formula, Solved Examples, Verification, FAQs
