Why is Earthing For Transformers So Important?

Table of Contents

1. Advantages of Earthing for Transformers:
2. Type of Earthing for Transformers:
3. Conclusion:
4. What are Earth Rods?
5. Myths of Chemical Earthing
6. EV Charging Station Safety – The Surprising Need for Earthing

Distribution Transformers are an important component of the power distribution network. They play a major role in providing an uninterrupted power supply to consumers. They are one of the most reliable components of the power grid, yet there can be situations where they fail. Electrical damages are one of the causes of transformer failure. This can be due to transient or overvoltage conditions caused by lightning or switching surges. Sudden failures or damages of transformers can result in unscheduled outages resulting in huge losses. Earthing for transformers can drastically reduce these outages and losses from it.

Advantages of Earthing for Transformers:

Earthing directs the excess current to the ground and thus provides protection. Earthing for transformer is extremely important for the safety of personnel and normal functioning of the system. Some of the main advantages of earthing a transformer system are listed below.

a)The low magnitude of transient over voltages.
b)Greater protection from lightning.
c)Reduction in frequency of faults.
d)Improved fault protection
e)Lesser maintenance requirements.
f)Higher safety for personnel.

 

Type of Earthing for Transformers:

Earthing for a transformer is done in two ways to ensure safety.
1) Body Earthing
2) Neutral earthing

1) Body Earthing:

The first earthing type for the transformer is Body Earthing. The body of the transformer consists of the oil tank, insulation, tap changer, conservator, breather etc. During a fault condition, leakage current flows through the body. Any person who comes in contact with the body has a chance of getting struck by severe shock. To avoid this situation body of the transformer is grounded. In the transformer body, mainly the tank is connected to the ground rod with two earth connections. This is also known as safety earthing or bonding. In body earthing, non-current carrying metal parts such as the tank, radiators, core etc. of the transformer are connected to the earth. The transformer body earthing terminal is connected to the medium voltage main earthing bar by an insulated copper earthing conductor. The body earthing for the transformer also provides protection from lightning incidents.

2) Neutral Earthing:

The second earthing type is Neutral Earthing. Under fault events or unbalanced loading conditions, current flows through the neutral wire to the ground. In a three-phase connection, there can be varying loads between the three phases. This unbalanced load can cause a fault current called a floating current. This fault current or floating voltage which is very dangerous can be avoided by providing a neutral earthing for the transformer. Also, if there is a fault in the transformer, star winding or the connected cables/bushings, the transformer will be isolated when there is a neutral earthing.

Consider that one of the phase lines is struck by lightning. The over-current is transferred to the other phases easily in such an instance. But if the system has a neutral earthing, this extra current gets directly grounded, and the system is safe from damage.
The neutral earthing also limits the over voltage on the non-faulted phases, which helps in lowering dielectric stress on the insulation system. This permits the use of surge arresters designed for earthed transformer systems. In multiphase distribution systems, this results in thinner insulation systems for cables and transformer windings, which can result in substantial cost savings.

Similar to body earthing, the neutral of the three-phase transformer is connected to a ground rod with copper earthing material. Transformer neutral (star point) is to be connected by an insulated earthing conductor directly to the independent earthing electrode.

 

Conclusion:

The earthing for a transformer and its housing must be intact to avoid accidents or damages caused by over voltages. Since these facilities deal with high power handling, there is a greater possibility of unexpected voltage fluctuations. Any such fault can be dangerous to the operating staff and the downstream equipment or loads.
Along with the earthing for the transformer, all other exposed non-current carrying metal parts of the transformer installation, including the fences, guards, pipings etc, should also be grounded and bonded for safety. Maintaining an equipotential ground can avoid the dangers of step and touch potential. Earth mats are one of the main earthing techniques used in such facilities for extra safety.

You can read more on Earth Mats in our previous blogs. Common lightning arresters also should be connected to the earth electrode, following the shortest path. These lightning arresters provide a dedicated path for the lightning current to the earth. Thus overall protection of the transformer and the housing is possible for safe power distribution.

SOURCE : https://axis-india.com/earthing-for-transformer/

Electrical Safety Auditing – Methodology & Scope

Table of Contents

1. Why is Earthing For Transformers So Important?
2. What is Maintenance Free Earthing?
3. Ground Potential Rise Study

 

We often hear about electrical accidents in commercial buildings, industries, and other facilities that cause huge losses like equipment, infrastructure and even human lives. These accidents often result from faulty or unsafe electrical practices or unnoticed worn-out electrical systems. The severity of the accident is increased with the absence of proper safety equipment or techniques. To eliminate such instances and accidents a periodic and thorough examination of all electrical installations in such facilities is required. This is the main objective of Electrical safety auditing. An electrical safety auditing is a systematic enquiry, inspection, testing and verification of the electrical systems performed by experienced professionals to reduce the risk and ensure compliance with the safety standards and regulations of the government.

Facilities for Electrical Safety Auditing: 

• Industrial areas, factories etc
• Commercial spaces
• Electrical distribution houses
• Hospitals
• Institutions and organisations

Objectives of Electrical Safety Auditing:

As mentioned above, the major aim of electrical safety auditing is to identify and eliminate the potential electrical hazards and increase the safety of an industrial or commercial area or any such building. Other objectives include:

a) Understanding the electrical performance and possible safety hazards in the system.

b) Increase the safety of equipment and personnel.

c) Improving the energy efficiency of the system and efficient use of resources.

d) Improving the life of electrical equipment and installations.

e) Identifying the possible improvements in safety techniques and practices

f) Checking compliance with safety standards and regulations.

Scope of  Electrical Safety Auditing:

The main goal of electrical safety is electrical hazard identification and risk assessment, as mentioned above. Let us now look into this assessment in detail. Following are the ways in which the degree of safety is measured, and some recommendations to reduce or eliminate the dangers of electrical hazards in a facility.

1) Check the earth resistance of earth pits and sockets.

2) Review of electrical preventive maintenance program within the facility.

3) Review the shutdown procedure, work permits, lock-out tags etc.

4) Review of earthing and lightning protection systems present in the factory/ plant/ facility to ensure human and equipment safety.

5) Review electrical networks and systems within the facility, focusing on the adequacy and functionality of protection devices.

6) Review of electrical documents like the register of electrical installations, single line diagrams, test records (transformer oil test, insulation resistance test, earth resistance test etc.) and data sheets of critical electrical installations.

7) Checking the hotspots within the electrical installations and equipment using a thermal imager.

8) Verification of proper warning signs and labelling of electrical panels, and other equipment.

9) Review of fireside system protection.

10) Review the records of coaching and competency of employees and contractors performing the trade.

11) Review the records of employees associated with electrical safety, electrical hazard management at the workplace etc.

12) Identify the training needs of personnel related to electrical safety.

Methodology of Electrical Safety Auditing:

The electrical safety auditing includes the review of the documentation, on-site visit, data collection, analysis and data verification with respect to industry norms and peer data. Let us look at the steps in detail.

Pre-audit meeting:

A pre-audit or audit planning meeting is the first opening meeting to discuss the guidelines with the management and other concerned departments. The onsite activities, procedures and preparation for the actual audit are done.

On-site inspection:

The site visit is done to identify the electrical hazards as per the scope of the audit. This includes inspection of all the electrical systems such as the incoming supply receiving section, all electrical equipment in the facility, cabling, earthing connections, lightning protection system, temporary wiring, possible electrical fire hazards etc. The verification of the installations is done with reference to the available drawings such as the single line diagrams, earthing layouts, etc.

Documentation review:

A review of all relevant documents regarding maintenance, testing, electrical inspection reports and other electrical records is done for the assessment of the facility.

Audit closing meeting:

The audit team meets and discusses their findings and recommendations with the members of the facility.

Final report submission:

Submission of the final electrical safety audit report to the client, with the recommendations and the agreed changes according to it.

The above-given steps complete the electrical safety auditing for a facility. By understanding the objectives, scope and methodology of performing an electrical safety auditing we learn its importance. We see that Electrical Safety Audit is a very important fact-finding exercise and gap analysis study focused on electrical issues to ensure the safety and reliability of the electrical installations. For any existing plant with no history of any electrical issues, a third-party audit can be conducted every 5 years. This is for the safety of the facility and the personnel working there and should be strictly followed.

LIGHTNING RISK ASSESSMENT

 

AN OVERVIEW

The lightning Risk Assessment study is extremely necessary as a result of if a building is hit by lightning hypothetically; it'll vaporize a wet layer between the walls of the building into steam and may cause an explosion of the wall that might cause a lot of harm to the instrumentation, individuals and conjointly the building itself. To require preventative measures from these, lightning risk assessments are done.

The goal and scope of the Lightning & Surge Protection Study are as follows:

• The main objective of a lightning protection system is to safeguard a structure from damages thanks to lightning strikes.
• Evaluate the condition of the current existing lighting protection system of a facility, and suggest recommendations if necessary.
• Make sure that the ability is compliant with international standards and laws that's needed by them.
• Study the maintenance aspects of lightning protection and recommend applicable corrective actions in the existing system.

ELECTRICAL SAFETY AUDIT IN INDIA

 

ELECTRICAL SAFETY AUDIT IN INDIA

The comprehensive Electrical Safety Audit is a methodical way to identify potentially hazardous electrical situations and to prescribe corrective actions for development, compliance with NFPA ® 70E and 70B, Indian Electricity Rules, Central Electricity Authority, OSHA, electrical safety work processes, maintenance tools, and to identify potential costs savings and inefficiencies through modification of electrical systems.

It is utilized to determine a site’s electrical safety behaviour. It provides guidance to help companies establish a practical safe working area for employees who are exposed to electrical hazards arising from the use of electricity in activities such as installation, maintenance, and uninstallation of equipment. This audit is an opportunity to assess the company’s status in regards to adherence to specific electrical safety regulations, Indian Electricity Rules, Central Electricity Authority NFPA ® 70E and 70B, OSHA, electrical safety work processes and electrical best practice behaviours.

TYPICAL SCOPE OF THE STUDY – ELECTRICAL SAFETY AUDIT

• Verification of compliance as per requirements of IEC 60204, NFPA, Indian Electricity Rules & Central Electricity Act.
• Physical inspection of the plant with reference to applicable Indian Standards, Indian Electrical Rules and other relevant codes of practice and identifying hazards (shock, fires etc.,)
• Inspection of the electrical equipments, Machinery and components of a system safe installation, adequacy for normal load and fault levels, safety for normal operation;
• Review of the importance given to electrical safety in the company safety policy, safety committee, continuous electrical risk identification, etc.
• Review of protection devices/system of the electrical installation.
• Review of adequacy of cables, motors, etc. Based on actual load current measurements and cable current carrying capacities.
• Review of electrical incidents to identify root cause of the incidents.
• Review the EPM (Electrical Preventive Maintenance) program in the premises & to examine documentation, checklist, etc.
• Review of earthing system (installation and maintenance aspects), including sample Earth Resistance tests
• Survey of electrical mischances and close misses in the plant to distinguish the underlying drivers.
• Identification of hot-spots in electrical installation using thermal cameras.
• Review of static electricity hazards in the Electrical System/Installation operations as per IS 7689;
• Audit of electrical systems & techniques (work permits, interlocks, lockout labels).
• Evaluating the honesty of protection of links via doing protection resistance tests on a specimen premise.
• Audit of Personal Protective Equipment for electrical works.
• Supply main incomer Cable insulation testing shall be done on sample basis;
• Testing: Panel wise detailed compliance; RCCB trip testing

 

ISO 45001 ELECTRICAL SAFETY PROCEDURE

This ISO 45001 electrical safety procedures template can assist your business comply with ISO 45001, Occupational Health and Safety Management System clauses:

• 6.1. Actions to Address Risks and Opportunities.
• 6.1.2. Hazard Identification and Assessment of Risks and Opportunities.
• 8.1.2. Eliminating Hazards and Reducing OH&S Risks.

Description

Electrical Safety Overview

Electrical safety refers to the careful manner in which workers who are exposed to the risks of electricity, electrical systems and electrically powered equipment conduct their work. Electrical safety relates to any method or guideline that workers follow to mitigate electrical hazards and risks and prevent incidents with electricity. Non-compliance with electrical safety procedures and safe work practices can lead to very serious incidents or even fatalities.

What is Electrical Work?

Electrical work refers to any work that is connecting or disconnecting electricity supply wiring to electrical equipment, or manufacturing, constructing, installing, removing, adding, testing, replacing, repairing, altering or maintaining electrical equipment or an electrical installation.

What are Electrical Safety Procedures?

Due to the intrinsic risk when working with electricity it is extremely important to follow electrical safety procedures to avoid injury or death. Electrical safety procedures will detail the many safety precautions and safety control measures that persons at risk need to be aware of if exposed to potential electrical hazards and risks and to work safely.

Below are just a few of the safety control measures and some safety tips that need to be followed when working with electrical equipment and electrical installations:

• Electrical work must only be performed by licensed and competent persons.
• All electrical work must comply with the relevant standards, national codes and other relevant legislation.
• All persons must be competent in the electrical equipment they intend on using and/or the electrical work they plan on performing.
• Unauthorized alterations of electrical equipment or installations must not be undertaken under any circumstances.
• Persons must be aware of the safe work requirements with electrical cords, power lines, short circuit electrical fires, energized circuits, circuit breakers, etc.
• All necessary electrical personal protective equipment (PPE) such as rubber gloves, non-conductive shoes and safety glasses must be worn.

Note: persons performing electrical work must be provided with adequate information, training and supervision to enable compliance with all applicable electrical safety legislation.

Contents of this ISO 45001 Electrical Safety Procedure

• Approval.
• Purpose.
• Scope and Objectives.
• Terms and Definitions.
• Roles and Responsibilities.
• Procedures.
• Electrical Work.
• Licensing.
• Inspection and Testing of Electrical Equipment.
• Electrical Equipment Register.
• Working Near Overhead or Underground Electrical Lines.
• Safety Observer.
• Electrical Circuits.
• Contact with Electrical Assets.
• Electrical Installations.
• Power Cords, Extension Cords and Extension Sets.
• Electrical Shock Response.
• Use of Portable Electrical Equipment.
• Electrical Isolations.
• Electrical Equipment in Hazardous Areas.
• Use of Electrically Conductive Ladders.
• Performing Live Work.
• PPE for Live Work.
• Related Procedures, Forms and Documents.
• Review Criteria.
• Record Management.
• References.

Shri Bhupender Yadav calls upon the BRICS nations for urgent concrete climate actions

Shri Bhupender Yadav calls upon the BRICS nations for urgent concrete climate actions

Posted On: 28 JUN 2023 9:36PM by PIB Delhi

The 9th BRICS Environment Ministers Meeting was held today under the theme of theme, “Advancing Environmental Cooperation amongst BRICS towards the attainment of the 2030 Agenda for Sustainable Development,” through video conferencing under the Presidency of South Africa. Prior to this meeting, a meeting of the senior officials took place on 27th June to finalize the outcome documents, to be adopted during the BRICS Environment Ministerial.

Representing India, the Union Minister of Environment, Forest and Climate Change, Shri Bhupender Yadav stated that the Implementation Plan of the BRICS Environment MoU signed in July 2018 can be a platform for exchange of knowledge, information, ideas, best practices, etc. among the BRICS nations.

Shri Yadav called upon the BRICS nations for urgent concrete climate actions, and to intensify the efforts for saving the planet.

The Union Minister elaborated on the efforts made by India for protection of environment and for combatting climate change, pollution and biodiversity loss. He also shared the major initiatives taken by the India under the dynamic leadership of Hon’ble Prime Minister, Shri Narendra Modi.

Highlighting the significance of Mission LiFE, launched by the Prime Minister, Shri Yadav stated that Mission LiFE is also about adopting lifestyle change to tackle climate change, biodiversity loss and pollution at all levels including at the individual level.

Shri Yadav urged that finance and technology partnerships are the key pillars for the BRICS Nations to foster greater efforts to combat climate change and to protect biodiversity while joining hands for ensuring environmental justice; climate justice; fair, just and inclusive transition.

Unique package for farmers announced

Unique package for farmers announced

CCEA approves bouquet of schemes to boost wellbeing of farmers, rejuvenate soil productivity, and ensure food security & environmental sustainability

CCEA approves continuation of Urea Subsidy Scheme; Rs. 3,68,676.7 Crore committed for urea subsidy for 3 years (2022-23 to 2024-25).

Rs. 1451 crore approved for Market Development Assistance (MDA) Scheme to exemplify model of wealth from waste; Parali and organic manure from Gobardhan plants to be used to enrich the soil and keep the environment safe and clean

Introduction of Sulphur coated Urea (Urea Gold); to address Sulphur deficiency of soil and save input costs for the farmers

Posted On: 28 JUN 2023 3:51PM by PIB Delhi

The Cabinet Committee on Economic Affairs (CCEA) chaired by Prime Minister, Shri Narendra Modi today approved a unique package of innovative schemes for farmers with a total outlay of Rs.3,70,128.7 crore. The bouquet of schemes is focused at overall wellbeing and economic betterment of farmers by promoting sustainable agriculture. The initiatives will boost farmers’ income, strengthen natural / organic farming, rejuvenate soil productivity, and ensure food security.

The CCEA approved continuation of Urea Subsidy Scheme to ensure constant availability of urea to the farmers at the same price of Rs 242/ 45 kg bag excluding taxes and neam coating charges.  Out of above approved package, Rs. 3,68,676.7 Crore have been committed for urea subsidy for three years (2022-23 to 2024-25). This is apart from recently approved Nutrient Based Subsidy of Rs 38,000 Crore for Kharif season for 2023-24. The farmers need not spend extra for purchase of urea, and this will help moderate their input costs. At present, the MRP of urea is Rs.242 per 45 kg bag of urea (exclusive of charges towards neem coating and taxes as applicable), whereas the actual cost of the bag comes around Rs. 2200.  The Scheme is wholly financed by the Government of India through budgetary support. The continuation of Urea Subsidy scheme will also maximize indigenous production of Urea to reach self-sufficiency levels.

Due to ever changing geopolitical situation and increased raw material prices, Fertilizer prices have been increasing multifold globally over the years. But Government of India has protected its farmers from steep fertilizer price rise by increasing the fertilizer subsidy. In its endeavour to safeguard our farmers, Government of India has increased Fertilizer subsidy from Rs. 73,067 Cr in 2014-15 to Rs. 2,54,799 Cr in 2022-23.

Nano Urea eco-system strengthened

By 2025-26, eight Nano urea plants with production capacity of 44 Crore bottles equaling to 195 LMT of conventional urea will be commissioned. Nano fertilizer releases nutrients in a controlled manner contributing to higher nutrient use efficiency and while costing less to the farmers. Application of Nano Urea has demonstrated increase in crop yield.

Country on way to become Atmanirbhar in Urea by 2025-26

Setting up and revival of 6 urea production units at Chambal Ferti ltd. - Kota Rajasthan, Matix ltd. Panagarh West Bengal, Ramagundam-Telangana, Gorakhpur-UP, Sindri-Jharkhand and Barauni-Bihar since 2018 is helping to make the country atmanirbhar in terms of urea production and availability. Indigenous production of urea has increased from the level of 225 LMT during 2014-15, to 250 LMT during 2021-22. In 2022-23, production capacity has increased to 284 LMT. These along with Nano Urea Plants will reduce our current import dependency in urea and finally make us self-sufficient by 2025- 26.

PM Programme for Restoration, Awareness Generation, Nourishment and Amelioration of Mother – Earth (PMPRANAM)

Mother Earth has always provided plentiful sources of sustenance to mankind. It is the need of the hour to go back to more natural ways of farming and promotion of balanced / sustainable use of chemical fertilizers. Promoting natural / organic farming, alternate fertilizers, innovations like Nano  Fertilizers  and  bio-Fertilizers can help in restoring fertility of our Mother Earth. Thus, it was announced in the Budget that “PM Programme for Restoration, Awareness Generation, Nourishment and Amelioration of Mother – Earth (PMPRANAM)” will be launched to incentivize States/ Union Territories to promote alternate fertilizers and balanced use  of chemical fertilizers.

Rs. 1451.84 crore have been approved for Market Development Assistance (MDA) for promoting Organic Fertilizers from Gobardhan Plants

Today’s approved package also consists of innovative incentive mechanism for the restoration, nourishment, and betterment of the mother earth. Market Development Assistance (MDA) scheme in the form of Rs 1500 per MT to support marketing of organic fertilizers, viz., Fermented Organic Manures (FOM)/Liquid FOM/Phosphate Rich Organic Manures (PROM) produced as by-product from Bio- gas Plants/Compressed Biogas (CBG) Plants set up under umbrella GOBARdhan initiative.

Such organic fertilizers would be branded in the names of Bharat Brand FOM, LFOM and PROM. This on one hand will facilitate in addressing the challenge of management of crop residue and problems of Parali burning, will also help in keeping the environment clean and safe and at the same time provide an additional source of income for farmers. Farmers will get organic fertilizers (FOM/LFOM/ PROM) at affordable prices.

This initiative will facilitate implementation of Budget announcement of establishing 500 new waste to wealth plants under GOBARdhan scheme for promoting circular economy, by increasing the viability of these BG/CBG plants.

Promotion of Natural Farming as sustainable agriculture practice is restoring soil health and reducing input costs for farmers. 425 KVKs (Krishi Vigyan Kendras) have laid down demonstrations of natural farming practices and organized 6,777 awareness programs involving 6.80 lakh farmers. Course curricula for Natural Farming has also been developed for BSc as well as MSc programmes to be implemented from the academic session July-August 2023.

Introduction of Sulphur coated Urea (Urea Gold); to address sulphur deficiency of soil and save input costs for the farmers

Another initiative of the package is that the Sulphur coated Urea (Urea Gold) is being introduced in the country for the first time. It is more economical and efficient than the currently used Neem coated urea. It will address Sulphur deficiency for the soil in the country. It will also save input costs for the farmers and also raise incomes for farmers with enhanced production & productivity.

Pradhan Mantri Kisan Samruddhi Kendras (PMKSKs) touches one lakh

About one lakh Pradhan Mantri Kisan Samruddhi Kendras (PMKSKs) have already come up in the country. For the convenience of farmers, the farm inputs are being provided as a one stop solution for all needs of farmers.

Benefits:

The approved schemes will help in judicious use of chemical fertilizers, thereby reducing input cost of cultivation for the farmers. Promoting natural/ organic farming, innovative and alternate fertilizers like Nano Fertilizers and organic fertilizers will help in restoring fertility of our Mother Earth.

1. 1. Improved soil health leads to increased nutrient efficiency and safe environment due to reduction in soil and water pollution. Safe and clean environment helps in improvement in human health.
   2. Better utilization of crop residue like parali will help resolve the issue of air pollution and improve the cleanliness and betterment of living environment and also help to convert waste into wealth.
   3. Farmers will reap more benefits – they need not pay anything extra for urea as it continues to be available at the same affordable statutory price. Organic fertilizers (FOM/ PROM) will also be available at cheaper prices. With low-cost Nano urea and reduced use of chemical fertilizers and increased use of organic fertilizers, the input cost for the farmers will come down. Low input cost coupled with healthy soil and water will enhance the production and productivity of the crops. Farmers will get good returns for their produce.