global electrical safety
TRANSCRIPT
Electrical Accidents-Statistics
• •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
• 25% of all fires occur due to electricity
• 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
• 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
Global Developments in Electrical Safety
• Electrical Safety Products
•ES Auditing Techniques
•ES System Certifications
• Electrical Risk-Based Maintenance System
•Electrical RM Programme
ES Products...
• Residual Current-Operated Circuit Breakers (RCCBs)
•Arc Fault Current Interrupters (AFCIs)
• Glowing Connection Detector (GCDs)
•Infra-Red Hotspot Detection Tool
•Thermography Surveys
ES Products
• Automatic Defibrillators
•Complete Home ES Kit
• Automatic Fire Detection & Extinguishing System
•Electrical Product Safety Recalls
•Linear Heat Sensing Cables (LHSC)
GFCIs & RCCBs
•GFCIs - 5 mA, RCCBs - 30, 100, 300 mA
•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
• GCs are fires waiting to happen
•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
• Used as part of effective EPM
•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
• Halogen-Free Fire Retardant 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)
•250,000 deaths every year due to sudden cardiac arrest
•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
• Advantageous than detectors, more effective
•LHSC applications:
•Cable trays in cable galleries
•Transformers
•Switch gears
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
• Cutler Hammer, USA offers Home Safety kit, comprising of:
•Surge protector
•GFCI
•AFCI
•MCBs
Electrical Product Safety Recalls
•Part of product liability
•Electrical products recalled:
•Power tool battery packs (defective battery fixings)
•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
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
ES System Certification
• Integrated Occupational Health & Safety Management System certification (OHSAS 18001)
•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
•Reconstruction of electrical fires
•Major electrical equipment failures (MBD)
•Investigation of Transformer fires
•Bus duct failures
Electrical Risk- Based Maintenance
• Risk & Reliability based Maintenance Schedules
•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 strikes only the tall objects/ structures
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
HAC Risk Assessment
•Extension to the existing HAC approach
•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 Continous Frequent Infrequent Very Infrequent
Continous Unacceptable Unacceptableunless lowconsequences
Acceptable(e.g. Ex iapparatus)
Primary Unacceptable Unacceptable Risk Assessmentrequired-look atconsequences
Acceptable (e.g.Ex d apparatus )
Secondary Risk Assessmentrequired-look atconsequences butprobablyunacceptable
Risk Assessmentrequired-look atconsequences but
Acceptable(E.g. Ex napparatus)
Acceptable
Non-Hazardous Acceptable butexaminecatastrophicreleases
Acceptable butexaminecatastrophicreleases
Acceptable Acceptable
Grade of Ignition
Risk-Based ES Audit
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•Need for Electrical Safety is universal
•ES awareness is increasing
•Partnership between regulators, employers, manufacturers- growing
•Many injuries are prevented
•Learning from experience- very essential
•Innovative ES devices are being used by people
Much More to be done in the field of ES in India!!
