Today’s modern society is highly dependent on electrical power supply. To live & make our life comfortable, we use number of appliances or gadgets at our residence or office.
Electrocution, Electrical fire and Lightning kill 15,000 people a year. Also, 75,000 (approx.) people suffer because of these deaths as there is loss of property and assets, dreams of many people associated with deceased shatter.
Around 1 lakh people died due to electrocution in the last decade, as per NCRB data (please refer table 1).
The news of electric shock or electric fire killing people gives pain and forces everyone to find the solution, but in a day or two we again forget and wait for another accident to happen. (Refer figure 1).
There are too many tales that different parts of the country have to tell each day without fail (many cases are even not reported or recorded).
Keeping the figure for the injured aside, the numbers for the electrocution deaths in the country tell a story of their own. According to the National Crime Records Bureau, around one lakh people lost their lives because of electrocution in the last decade alone. The annual average of fatalities rose to 12,500 per year or 30 fatalities every day.
Calling the 30 electrocution deaths per day in India ‘accidents’ is something that is not justified as it tends to insulate all stake holder from accountabilities.
Main Causes of Electrocution & Electrical Fire Hazard
Electrocution & Electrical Fires in an Electrical Installation may be broadly caused by:
- Over currents (overloads and short circuits)
- Harmonics
- Earth fault
- Electric arcs in cables and loose Connections
- Failure of protection device or Wrong selection of protection device
- Wrong selection of cables or wires
- Mismatch of illumination fittings rating and lamps used
- Use of extension cord for heaters or any other heavy loads
- Use of outlived (outdated) or damaged equipment
- Over voltages (Lightning) & arcing ground
- Consumer has become prosumer
- Inadequate design for earthing or grounding
- Improper or No verification and testing (commissioning or periodical)
Role of Adequate Earthing or Grounding
Grounding or earthing means making a connection to the general mass of earth. The use of grounding is so widespread in an electric system that at practically every point in the system, from the generators to the consumers’ equipment, earth connections are made.
There are two types grounding (Refer figure 2):
- Neutral Grounding
- General (Equipment) Grounding
The objectives of General Grounding system include:
- To provide a low resistance return path for fault current, which further protects both working staff and equipment installed in the premises (Refer figure 3).
- To prevent dangerous GPR with respect to remote ground during fault condition.
- To provide a low resistance path for power system transients such as lightning and over voltages in the system.
- To provide uniform potential bonding /zone of conductive objects within substation to the grounding system to avoid development of any dangerous potential between objects (and earth).
- To prevent building up of electrostatic charge and discharge within the substation, which may result in sparks.
- To allow sufficient current to flow safely for satisfactory operation of protection system.
The main objective of grounding electrical systems is to provide a suitably low resistance path for the discharge of fault current, which ultimately provides safety to working personnel and costly installed equipment by providing sufficient current to safety devices.
Basic of Short Circuit in the Electrical System
Electrical fires very often take place in residential sector. This is because most of the people do not account for the rating of the appliances while placing or connecting them. Being an individual, most of us are not aware about the parameters we need to consider while purchasing the product. The only thing that people look for is the cost effectiveness, which in turn leads to extreme situation resulting in electrical fires. Major reason for electrical fire in LV system is Short Ciurciting i.e., flowing of current through unintended path.
A short circuit is an abnormal connection between two nodes of an electric circuit intended to be at different voltages. This results in an electric current limited only by the equivalent resistance of the rest of the network, which can cause circuit damage, overheating, fire or explosion (please refer figure 4).
This high current generates high heat and presence of fuel or any other flammable materials may result in the fire hazard as governed by fire triangle in figure 5.
Short circuit happens mainly due to degradation of insulation. As the wire gets old, the insulation gets degraded, due to which there is a chance of short circuiting (figure 6) & this may lead to fire.
Main Causes of Electrocution and Electrical Fire – Different Locations
Electrocution and fire hazards pose significant risks to individuals and properties in various settings, including homes, commercial buildings, public places, public processions and substations. These hazards can result in devastating consequences, including loss of life, injuries, and extensive property damage. Understanding the causes behind these incidents is crucial for implementing preventive measures and ensuring safety in these environments. In this section, we will explore the primary causes of electrocution and fire in each of these settings.
Electrical Safety at Home & Commercial Shops
Electricity is not something to play around with – negligence and carelessness lead to both electrocution and fire at our homes. Homes are where individuals spend a significant portion of their time, making them susceptible to electrical hazards if proper precautions are not taken.
Commercial buildings house various electrical systems to support operations, making them susceptible to electrical hazards if not adequately maintained. Several factors that contribute to the risk of electrocution and fire in residential as well as commercial places are given the table 2 below:
Electrical Safety at Public Places
Public places, such as schools, hospitals, shopping malls, and recreational facilities, accommodate large numbers of people, making electrical safety paramount (refer figure 7). Electrocution in public places is also evidence of power companies and governments cutting corners. Safety requires DISCOMs to take all high-tension cables underground. But power companies resist this for the costs entailed and direct impact on electricity tariff.
Causes of electrocution and fire in public places (apart from above causes in table 2) are discussed below:
- Aging Infrastructure: Older public buildings may have outdated electrical systems that are more prone to faults and failures, increasing the risk of electrical accidents.
- Lack of Maintenance: Inadequate maintenance of electrical systems and equipment in public facilities can lead to deteriorating conditions and potential hazards.
- Overcrowding: Events or facilities that experience overcrowding may put strain on electrical systems, increasing the likelihood of overloads and electrical fires.
- Improper Installation: Faulty installation of electrical systems or equipment in public places can create hazardous conditions that endanger occupants and visitors.
- Vandalism or Sabotage: Deliberate acts of vandalism or sabotage targeting electrical infrastructure in public places can result in electrocution hazards and fires. (Refer figure 8)
Electrical Safety at Public Gathering & Processions
Public processions and gatherings hold significant cultural, religious, and social importance in India, often involving large crowds congregating on streets. However, amidst the fervor and celebration, safety concerns often take a backseat, leading to tragic incidents like electrocution & fire.
Causes of Electrocution
- Improper Wiring: Inadequate or faulty wiring setups are common during public events due to hasty installations or lack of expertise. These setups may include temporary electrical connections that are not insulated properly, increasing the likelihood of electrocution if they come into contact with water or damp surfaces.
- Overloaded Circuits: The demand for electricity surges during festivals and processions due to extensive lighting arrangements, sound systems, and other electrical paraphernalia. Overloading circuits beyond their capacity raises the risk of short circuits and subsequent electrocution hazards.
- Poor Maintenance: Existing electrical infrastructure often receives minimal maintenance, exacerbating risks during public gatherings. Aging cables, corroded connections, and neglected equipment pose significant threats when subjected to the additional strain of large-scale events.
- Unauthorized Installations: In the rush to set up for festivities, unauthorized installations by unqualified personnel are common. These makeshift arrangements bypass safety protocols, heightening the probability of accidents such as electrocution.
- High-Tension Wires: High-tension wires, also known as high-voltage power lines, carry electricity over long distances at high voltages. These wires are typically installed on tall transmission towers or poles to ensure clearance from the ground and surrounding structures. However, during public processions, temporary structures such as stages, pandals (decorative tents), or banners may inadvertently come into contact with these wires, leading to catastrophic consequences. (Refer figure 9)
Causes of Electrocution Due to High-Tension Wires
- Inadequate Clearance: Temporary structures erected for public processions often lack proper planning and supervision, resulting in insufficient clearance between the structures and overhead high-tension wires. Failure to maintain adequate distance increases the risk of accidental contact, especially when structures sway due to wind or crowd movement.
- Ignorance and Negligence: Organizers and participants may lack awareness about the dangers posed by high-tension wires or fail to recognize the potential hazards associated with erecting structures near them. Ignorance coupled with negligence in adhering to safety guidelines exacerbates the risk of electrocution incidents.
- Lack of Coordination: Coordination between event organizers, local authorities, and power distribution companies is often inadequate, leading to haphazard planning and implementation of safety measures. Failure to coordinate activities such as route planning, structure placement, and crowd management increases the likelihood of accidents involving high-tension wires.
- Encroachment and Unauthorized Construction: Encroachment on public spaces and unauthorized construction near high-tension wire corridors is a common phenomenon in many Indian cities and towns. Informal settlements, temporary shelters, and makeshift structures often encroach upon the safety buffer zones around high-tension wires, heightening the risk of electrocution during public processions.
Electrocution due to contact with high-tension wires during public processions represents a preventable tragedy that underscores the need for concerted action and collective responsibility. By raising awareness, enforcing regulations, conducting pre-event inspections, integrating safety into structural planning, and enhancing emergency response preparedness, India can mitigate the risks associated with high-tension wires and ensure the safety and well-being of its citizens during festive celebrations. Only proactive measures and collaborative efforts can help in getting rid of danger of electrocution from India’s public gatherings, allowing communities to celebrate their cultural heritage in safety and solidarity.
Electrical Safety at Industrial Location, Generating Station & Substations
Industries, generating station and substations are critical components of electrical networks, but they also pose significant risks if safety measures are not strictly enforced (Refer figure 10). Causes of electrocution and fire in substations include:
- High Voltage Exposure: Industries & substations contain high-voltage equipment that poses a severe risk of electrocution to untrained personnel or trespassers who come into contact with live components.
- Equipment Failure: Malfunctions or breakdowns of transformers, circuit breakers, and other substation equipment can result in electrical arcs, sparks, and fires.
- Lack of Proper Enclosure: Unprotected or poorly enclosed panels or substations may expose electrical components to environmental factors such as moisture, debris, and wildlife, increasing the risk of failures and fires.
- Inadequate Security Measures: Substations that lack sufficient security measures are vulnerable to unauthorized access, which can lead to tampering, theft, or vandalism that compromises safety.
- Insufficient Training: Workers at factories or substations must receive comprehensive training on electrical safety protocols and emergency procedures to mitigate risks effectively.
Seven Golden Rules to ensure safety for industrial locations and substation or generating station are given below in the table 3.
Electrocution and Fire Hazards Due to Contact with Overhead Power Lines or Snapping & Failure of Distribution Transformer
India’s rapid urbanization and industrialization have led to an exponential increase in demand for electricity. As a result, the country has witnessed a significant expansion in its power network infrastructure, including overhead power lines and distribution transformers. However, this growth comes with inherent risks, particularly concerning electrocution and fire hazards due to the snapping of overhead power lines and malfunctioning distribution transformers.
To be continued…
Dr. Rajesh Kumar Arora obtained the B. Tech. & Master of Engineering (ME) degrees in Electrical Engineering from Delhi College of Engineering, University of Delhi. He completed his PhD in grounding system design from UPES, Dehradun. He is also a certified Energy Manager and Auditor. Presently he is working in D&E (Design and Engineering) Department of Delhi Transco Limited (DTL). His research interests include high voltage technology, grounding system, protection system, computer application and power distribution automation.
