2. In this presentation……
Section I
Electrical hazards
Electrical accidents – Statistics
Humans & Electricity
Electrical Safety Programme elements
Section II
Global Developments in Electrical Safety
3. Electrical Accidents-Statistics
• • 25% of all fires occur due to electricity (NFPA)
• 411 deaths from job related electrical accidents
per year (NIOSH)
• Electrocution - the fifth leading cause of death
(1982 - 1990) NIOSH
•About 12 deaths due to electrocution NCRB,
(India)
•42 % of total fires occur due to electrical
sources (Source -OISD)
• 8% deaths that occur in Indian factories are due
6. Electrical Near-Misses &
Accidents- Major Causes
Working on live equipment w/o
authorization or PPE
Wiring mistakes coupled with failure of
safe-energy conditions
Leaving unsafe conditions
7. Electricity and People
A person usually offers a lesser resistance
for the electricity
The person forms a completed circuit when
touching the ground
Electricity always tries to travel to ground
8. ELECTRICAL FIRES ….
ELECTRICAL FAULTS (Contd.)
– STATIC DISCHARGES
– LIGHTNING
– USING ORDINARY ELECTRICAL EQUIPMENT IN
HAZARDOUS AREAS
9. Earthing
Most electrical equipment is designed with a
earthing system
Earth all equipment with metallic body (TVs?)
Double & Single earthing- differentiation?
Carry out ER tests annually as per NFPA 70
Take action on high ER values
Identify all earth pits, maintain a Earth Pit lay out
10. Earth Leakage Circuit Breakers
ELCBs reduce the likelihood of fatal shocks
Detect small amount of leakage current and
automatically switch off the power
Can be used with extension cords and portable
tools
Fuses and circuit breakers protect equipment,
not people
Use the right sensitivity ELCBs (30, 100, 300
mA)
11. Static Electricity
Created when materials rub together
Can cause shocks or even minor skin burns
Can damage sensitive electronic equipment
Reduced or prevented by:
– Proper grounding
– Anti-Static rubber matting
– Bonding & earthing of equipment, pipelines
12. Electrical Fire Protection
Use Linear Heat Sensing cables in cable
cellars along with smoke detectors
Consider all major electrical fires in EMP
Install master control switches outside all
stores
Maintain PFEs for electrical rooms
Consider local flooding systems for critical
panels/ switchgear panels
13. Case Study
An electrician received a shock while trying to
replace a tube light ballast in live power
condition.
He touched a live conductor. He was not wearing
rubber gloves. Current entered his right hand
through his little finger and exited through his
left hand.
Post Accident Correction:
– Working on live circuits not permitted
– LOTO to be strictly enforced
14. Equipment Operators
Never tamper with electrical interlocks
Do not repair electrical components of
your machine
Properly shut off machinery before
operation
Obey warning signs and follow safe
procedures
Follow PTW procedures strictly
15. Electrical Preventive Maintenance
Identification of critical Electrical Equipment
Emergency lighting
Fire Alarm System
Protection Supply DC System
UPS System, Battery Banks
Electrical Maintenance Procedures to be aligned with NFPA 70
B
17. Electrical Preventive
Maintenance
Implement EPM without slippage
Carry out all tests (ER, IR, transformer oil,
DGA, LP system, transformer protective
devices- simulation, FA system for electrical
rooms, etc.)
Adopt NFPA 70 E / B for electrical maintenance
Adopt Risk Based maintenance
Use predictive maintenance tools (hotspot
detector, Ultrasonic detectors, Thermography)
21. Present Status - ES-India
•ES Awareness is slowly growing
•Use of RCCBs in the rise, finer details are yet to
be understood by many
•More ES workshops / seminars are conducted in
India
•Statutory regulations are enforced strictly
(Karnataka, Delhi - Use of RCCBs mandatory in
residential buildings)
•Many industries are re-aligning their Electrical
practices based on international standards
(NFPA, IEEE, etc.)
22. Evolvement of ES Standards / organizations-
United States
•NFPA - NEC (1897)
•NESC (1913), from IEEE
•NIOSH (Research example: development of
voltage detector that will signal the person if he
gets close to live power)-1970
• OSHA (1970)
•NFPA 70 E & B (1979) -approved by OSHA
•Electrical Trauma Centre, Chicago (1990)
•NESF(1994), by UL, NFPA, NEMA, CPSC
24. ES Auditing Techniques
• Electrical Risk Assessment using Semi-
Quantitative Risk Ranking (SQRR) technique
•Emergency Lighting Risk Assessment
• Benchmarking against applicable standards:
•NFPA 780 Lightning Protection
•NFPA 70 M Electrical Preventive
Maintenance
•NFPA 70 E Personal Safety from Electrical
Safety
25. Electrical Risk Assessment (SQRR
Technique)
Risk Ranking based on severity, probability
High Risk- Statutory Non-compliance, F&E hazards,
Shock hazards, Risks that could result in immediate
threat to life & property. Immediate correction
Medium Risk - Maintenance flaws,Operational issues-
correction at the next available opportunity.
Low Risk - Mainly improvement measures, long term
implementation
27. ES related Information
Indian Electricity Rule, 1956 (2000 rev.):
(MoP, CEA web site,http://powermin.nic.in)
Lightning Protection Risk Assessment:www.furse.com
National Electrical Safety Foundation: www.nesf.org
Free safety Power Point presentations: http://siri.org/
Electrical Accidents: http://www.safteng.net:
IEEE IAS ES WS –Delhi Dec. 2004
28. Standards & Codes
NFPA 70 E & B- E-Safety & Maintenance
NFPA 780- Lightning Protection
API RP 2003- Static Electricity
API RP 500- HAC
OSHA 29 CFR- part 1910- Arc Flash
NFPA 70- NEC
IEEE 1584- Arc Flash Protection
NFPA 77- Static Electricity
OSHA CFR 1926-Personnel Electrical Safety
29. Summary
Electricity will try to reach ground even if it
means going through a person
Earthing has an important role in ES
Always inspect power tools and cords and do
not use them if damaged
Do not attempt to repair electrical equipment
unless trained and qualified
Understand effects of Lightning- it could save
your life!
Major fires, explosions occurred due to ESD ,
lightning in flammable atmospheres
Editor's Notes
I.Speaker’s Notes:
Electricity will travel through a person because most often that person offers less resistance than the electrical user (i.e., machinery, power tool) that is currently on the circuit.
If the person is touching the ground, that person will form a completed electrical circuit. Now the electricity will prefer to travel through the person (less resistance) and to the ground.
How can birds safely sit on high-voltage electrical wires? Because they are not touching the ground, they do not form a completed circuit, so the electricity does not pass through them.
I.Speaker’s Notes:
Almost all electrical equipment is designed with some sort of grounding system so that if there is a problem such as a short circuit, the electrical current will go to ground through the grounding system rather than through the human body.
Do not use equipment with damaged grounding connectors. Some people might alter a 3-prong plug by cutting off the grounding prong so that they can plug into a 2-prong receptacle. This practice is not safe because you are bypassing an equipment safeguard and setting yourself up for an injury.
Another option is to use an adapter that converts a 3-prong system into a 2-prong system. Again, this interrupts the grounding connection. The adapters are not designed to send the current to ground if there is a problem.
I.Background for the Trainer::
If your company uses Ground Fault Circuit Interuptors (GFCIs), bring one in to demonstrate to the employees.
II.Speaker’s Notes:
GFCIs reduce the likelihood of fatal shocks by automatically switching off the power when a small amount of earth or grounded current is detected.
GFCI receptacles might be found in homes or hotels in the bathroom or kitchen where an electric appliance such as a hair dryer or toaster has a chance to fall into a sink full of water. If this occurred, the GFCI would automatically shut off the power to the receptacle. The receptacle would have to be manually reset.
GFCIs can also be portable and used with extension cords and power tools.
Fuses and circuit breakers operate at several Amps to allow the circuit to continue even when slightly overloaded. Remember, people are injured at the milliAmp level.
I.Speaker’s Notes:
Static electricity is very common in the workplace and at home. It is caused when two materials rub against each another and build up a charge of electricity. The static is finally dissipated when a grounded conductor, such as a doorknob, is touched.
Sometimes static electricity can result in arcs of electricity leaping from a person onto an operator’s metal console. This type of static electricity can cause minor skin burns. It can cause dangerous shocks for people with heart conditions.
Static electricity can be reduced by properly grounding the equipment, providing rubber matting (i.e., increased resistance) for the operator to stand on, or providing PPE such as grounding wires that connect to a worker’s wrist, gloves, or shoes.
I.Speaker’s Notes:
Never tamper with or bypass electrical interlocks or other machine safeguards. You are risking injury to yourself and others every time you do this.
Do not attempt to repair electrical components of your machine. Do not even open your machine’s electrical panel. Remember, only authorized workers are permitted to repair or work on electrical equipment.
Properly disengage or shut off your machine before working in its point of operation. This may mean hitting the emergency stop or even calling an authorized worker to lock out the machine first.
Obey warning signs and stickers, particularly those that warn of high voltage.
Learn to identify electrical malfunctions of your machine.
I.Speaker’s Notes:
This slide lists the main points to remember when working with electricity.
