Electrical Safety.ppt

Best valueP.G. Sreejith
www.cholaaxa.com
India
Almost 12 people die due to electrocution every day (Source -NCRB)
42 % of total fires occur due to electrical sources (Source -OISD)
8% deaths that occur in factories are due to electricity
Electrical Accidents-Statistics
United States
411 deaths from job related electrical accidents per year (NIOSH)
Electrocution - the fifth leading cause of death (1982 - 1990) NIOSH
Present Status - ES-India
ES Awareness is slowly growing
Use of HRCs /RCCBs is 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.)
Various ES Standards / organizations-US
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)
Electrical Trauma Centre, Chicago (1990)
NESF(1994), by UL, NFPA, NEMA, CPSC
Global Developments in Electrical Safety
Electrical Safety Products
ES Auditing Techniques
ES System Certifications
Glowing Connection Detector (GCDs)
Infra-Red Hotspot Detection Tool
Electrical Product Safety Recalls
GFCIs & RCCBs
Delayed tripping RCCBs (200 mS)
AFCIs
Arcs - temperatures up to 20,000 degree C, Sun’s outer temperature- 5000 degree C
No material on earth can withstand arc temperature
RCCBs cannot detect arcing faults
AFCIs - the innovative ES device after RCCBs
AFCIs detects arcing waveforms and trips
AFCIs - mandatory in all US homes from 2002 January onwards
Arcing types
Arcing Waveforms
A loose wire at one terminal of a light bulb.
Arcing generated by a loose wire at a screw terminal.
GCDs
Loose connections at socket terminals will cause glowing connections
Use of GCDs- recommended by Forensic engineers
Glowing connections -will not detected by fuses, MCBs, RCCBs, AFCIs
GCDs operate at 83 degree C
Glowing connection hazards were detected by a UL study
Infra-Red Hotspot Detector
Hotspot surveys on critical, high capacity motor terminations, measurement of continuously running critical motors
Uses infra-red technology, with laser sighting
Does not penetrate glass, plastic
Interpretation of readings - very critical
HFFR Cables
Emits very low smoke, compared to PVC & even FRLS cables
Increasingly Used by many instead of FRLS (Fire Retardant low Smoke) cables
Thermography Surveys
Part of predictive maintenance
In the De-Terrified scenario, may be offered by general insurance companies
Identification of potential survey points / equipment and interpretation - very crucial
NFPA 70 E recommends Thermographic surveys
Automatic External Defibrillators (AED)
AEDs - to be part of Emergency Medical Kit
For every minute that passes w/o defibrillation, the chances of survival decreases by 10%
Has a voice prompt, cost USD 3000/-
UK - not a legal requirement, but a Statutory requirement in US
No legal liability for deaths involving the use of AEDs
Linear Heat Sensing Cables
LHSC applications:
Transformers
Automatic Fire D&E System
Fire Trace - local flooding application inside electrical switch gears / power panels- detects heat and the heat -sensitive tube punctures, letting out Ozone-friendly fire extinguishing gas
More ES Products
Non-Contact type voltage detector (magnetic field)
Plug-In Wiring Checker (detects 14 wiring defects, ideal for testing sockets, BS 1363, faulty N, missing E, reverse P& N)
Videoscanner, Metalliscanner (detects metallic pipes, conduits, rebar, within 15” concrete)
Home ES Kit
Surge protector
Building Wire (wrong earth wire identification)
IBM 15” PC monitor( overheating of electrical components resulting in smoke)
3 pin plugs (improper earth connection)
ES Auditing Techniques
Electrical Risk Assessment using Semi-Quantitative Risk Ranking (SQRR) technique
Usage of software to carry out Lightning Risk Assessment, Hazardous Area Classification
Electrical HAZOP (Electrical Hazard & Operability) studies
Electrical Hazard Spotting Exercises
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
ES System Certification
ATEX Certification (applicable to manufacturers / user industries, applicable in EU, mandatory by July 2003)
UL certification for Lightning Protection (based on NFPA 780 standard)
Electrical Fires & Forensic Investigations
Electrical Fires & Forensic Investigations
Forensic studies are commissioned by insurance companies in Japan, US, etc.
Product liability claims
Investigation of Transformer fires
Re-Aligning the Electrical Systems in Line with Specialized International Standards to Improve electrical Safety (IEEE, NFPA 70B)
Usage of Tools / Condition Monitoring Methods to have Effective Predictive Maintenance System
Lightning -Common Myths
Lightning does not strike the same object twice
You are safe inside a metal bodied car during lightning!
Electrical Risk Management Programme
Identification of electrical hazards
Risk Ranking (SQRR of electrical risks)
Risk Mitigation / Control using ALARP (As Low As Reasonably Practicable) principle
Continuous electrical hazard identification
Would be part of future European legislation
Presence of ignition sources considered in HAC
With this new HAC approach, the equipment optimization is expected to increase
New HAC-based Risk Assessment Matrix
Grade of Release
Secondary
Risk Assessment required-look at consequences but
Acceptable
Acceptable
Acceptable
Electrical Safety Audits focussed on potential risks
The audit methodology designed to identify all potential electrical risks (FTA, ETA, HAZOP, etc.)
Semi-Quantification of events using available failure data
Wrap-Up
ES awareness is increasing
Many injuries are prevented
Innovative ES devices are being used by people
Much More to be done in the field of ES in India!!
Technology can afford to get obsolete but not a technocrat!!
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