Electrical Safety

-Electrical Safety

In this presentation……

Section IElectrical hazardsElectrical accidents – StatisticsHumans & ElectricityElectrical Safety Program elements

Section IIGlobal Developments in Electrical Safety

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 to electricity

ELECTRICAL ACCIDENTS- 10 year Period, Chemical Industry

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

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

ELECTRICAL FIRES ….

ELECTRICAL FAULTS (Contd.)

– STATIC DISCHARGES

– LIGHTNING

– USING ORDINARY ELECTRICAL EQUIPMENT IN HAZARDOUS AREAS

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 70Take action on high ER values Identify all earth pits, maintain a Earth Pit lay out

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)

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

Electrical Fire Protection

Use Linear Heat Sensing cables in cable cellars along with smoke detectors

Consider all major electrical fires in EMPInstall master control switches outside all

storesMaintain PFEs for electrical roomsConsider local flooding systems for critical

panels/ switchgear panels

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

Equipment Operators

Never tamper with electrical interlocksDo not repair electrical components of

your machineProperly shut off machinery before

operationObey warning signs and follow safe

proceduresFollow PTW procedures strictly

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

Planning for EPM

Personal Safety

Equipment Failure

Production Economics

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)

‘All electrical accidents are preceded by rise in temperature & sound’

ELECTRICAL SAFETY AUDIT

A systematic approach to critically analyze the existing Electrical Procedures and Practices from safety point of view

Global Developments in Electrical Safety

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.)

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

ES Products...

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

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

RCCB Tripping

How do we solve this problem in India ?

Bypass it !!!

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

Standards & Codes

NFPA 70 E & B- E-Safety & MaintenanceNFPA 780- Lightning ProtectionAPI RP 2003- Static ElectricityAPI RP 500- HACOSHA 29 CFR- part 1910- Arc Flash NFPA 70- NEC IEEE 1584- Arc Flash ProtectionNFPA 77- Static ElectricityOSHA CFR 1926-Personnel Electrical Safety

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