Arc Flash Protection
Can Arc Flash Clothing Save Utility Workers Lives?
November 17th, 2017
Arc Flash Clothing – For Jointers Working On Low & High Voltage Power Cable Systems
Yes. Here is the evidence.
by Chris Dodds T&D - estimated reading time 5 minutes
Utility Workers & The Risk Of Arc Flash
Utility workers stand in the frontline of electrocution and arc flash risk – facing daily hazard whether in the cable trench, joint bay, substation or working in front of switchboard panels.
Jointers, Linesmen, SAP’s and Civil Engineers should all be protected against the working dangers of arc flash – according to the UK Health & Safety Executive workers engaged in the location, identification and excavation of of buried services should be ensure adequate protective clothing is used when working around underground cables:
HSG47 Excerpt
Injuries to workers are typically caused by the explosive effects of arcing current, also known as arc flash, and by the associated fire or flames that can result when a live cable is penetrated by digging tools (typically “shovels and spades”) – the risk is elevated where medium/high voltage cables are trenched and backfilled but not protected using 11kV/33kV cable covers.
Arc flash can also occur when a cable is crushed severely enough to cause internal contact between the cable conductors, or metallic cable sheathing and one or more conductors.
Injuries are severe – potentially fatal – burns to the hands, face and body: electric shock is possible but less likely.
Incidents can also arise from cables, connections and cable terminations which have been damaged but left unreported and unrepaired, or which have deteriorated with age.
Avoiding Danger From Underground Services UK HSE HSG47 – download full copy.
Here utility workers are shown live-line working from an aerial lift on overhead conductors from the bucket truck.
Insulating Matting | Voltage Detectors | Insulating Gloves | Insulating Sticks | Phase Comparators | Portable Earthing | Substation Safety Kits MV HV
Arc Flash – The Evidence
Pictured below are ProGARM arc flash polo shirts post-arc blast impact.
Clearly the garment has quelled the arc flash due to the inherent flame retardancy of the clothing fabric. The cause of the arc flash was triggered by an LV jointer using a Jack Hammer in the vicinity of an underground low voltage cable.
The strike to the 3 phase 120sqmm CNE utility cable caused an arc flash which if not protected against using appropriately rated clothing would have inflicted serious skin injury and burns to the cable jointers chest and arms.
Typical risks include: fuse replacement and maintenance on feeder pillars and link boxes, live cable jointing, underground cable excavation and switching operations in substations at low, medium and high voltages.
As well as correctly specified levels of arc flash clothing protection utility workers should ensure appropriate levels of protection against electrical shock hazard by wearing suitable insulating gloves, arc flash gloves and insulating boots according to the voltage and risk.
Cable Strikes & Arc Flash Risk
Failure to implement and follow the HSG47 Guidelines can cause fatal injury to workers striking buried electricity cables operating at LV MV HV – workers have been electrocuted and engulfed in flames coming into accidental contact with 11,000 volt (11kV) underground cable where sites have not been scanned for live buried cables by cable avoidance tools.
Cable strike incidents can be avoided when work is properly planned and supervised in accordance with HSG47.
Image: Lee Richard – LR Power Services
The photographs are compelling evidence of the electrical safety requirement to protect cable jointers whether working on LV, MV or HV power 
cables, overhead lines or substations.
The investment in clothing is an investment in worker protection and ultimately life.
Naturally, all ProGARM arc flash clothing is vigorously tested in the laboratory and to witness real life evidence of the protection provided underlines the need to take arc flash seriously.
Mark Lant, an Arc Flash Technical Expert at ProGARM comments: “Obviously, we’d prefer it if Arc Flash incidents never occurred. However, the fact is they do, and we’re pleased to see our arc flash polo shirt performing as effectively in the field as it did in the lab. We wish the cable jointer a speedy recovery from his other injuries.”
Arc Flash Clothing & Electrical Safety Tests
Arc flash clothing and garments are tested to European norms and standards:
- EN ISO 11612: 2008 (A1 B1, C1) – ISO 11612:2008 Protective Clothing – Clothing to protect against heat and flame
- EN1149-5: 2008 Pt 5: 2008, Pt 3: 2004 (Charge Decay) – Protective Clothing – Electrostatic Properties
- EN ISO 20471: 2013 Classs 3 – High Visibility Clothing – Test Methods & Requirements
- IEC 61482-2: 2009 Class 1 – Clothing Protection For Thermal Hazards Of An Electric Arc
Electric arc flash occurs during fault conditions when a current flows through an air gap between conductors – this inflicts catastrophic devastation upon switchgear MV HV
High Voltage Substations – pictured the catastrophic effects on 11kV switchgear and cables of an arc flash incident
Can An Arc Flash Occur While Ground Digging?
1. On average 8-10 cable strikes are reported in the UK every day
2. Over 90% of LV-HV underground cables in the UK are unmarked
3. Over 1,000 electrical incidents reported to the HSE in the UK every year
4. 25 of these are fatalities (HSE)
5. Fines can be an excess of £2 million
Arc Flash Learning & Resources
Thorne and Derrick are proud to be distributors of ProGARM arc flash coveralls and protection.
We can help – should you require arc flash calculators or advice on the type of clothing and protection available please do not hesitate to contact us.
Arc Flash Calculation – Selecting Clothing & PPE To Protect Lives Against Arc Hazard
September 20th, 2017-
by Chris Dodds T&D - estimated reading time 8 minutes
“30,000 Arc Flash Incidents per year” Source: ISHN
We recently asked Hugh Hoagland (Managing Partner at ArcWear & e-Hazard.com) to recommend the 3 most effective and reliable software packages for Calculating Arc Flash Risk & Hazard in accordance with NFPA 70E and IEEE 1584.ƒ1
e-Hazard USA are the industry leader in electrical safety training based on the latest NFPA 70E Standard providing arc flash testing, electrical safety and arc flash training for companies across the globe.
Hugh recommended the following Arc Flash Hazard, Risk Assessment, Clothing & PPE software packages: SKM, Easy Power and Kinetrics – we overview them and provide further information links to all 3 including free demonstration packages.
Arc flash clothing and PPE requirements are often panic rather than planned purchases – most often contractors are over-spending on arc flash protective clothing only to arrive on site to carry out work tasks requiring manual dexterity in cumbersome arc flash suits of armour. Hampered, overheating and under pressure to work safely in high voltage substations.
Electrical engineers must wear appropriate level of arc flash protection when working on low, medium or high voltage electrical switchgear, panels and equipment.
Consequently, it is rare for a specific site risk assessment or arc flash hazard calculation to have been carried out. Contractors therefore default to a “worst case” scenario with decision making clouded by the online plethora of inconsistent product recommendations often motivated more by commercial intent rather than the provision of worker safety.
We hope this information will enable better forward planning by contractors to minimise arc flash hazards by selecting the most appropriate level of protective clothing and utilising an arc flash sofware calculator.
As leading UK distributors of arc flash clothing, we are committed to supporting the observance and implementation of electrical safety and managing arc flash risk in hazardous and high voltage working environments.
Arc Flash | Jackets | Coveralls | Trousers | Sweatshirts | Helmets | Gloves ProGARM
Arc flash can occur during live cable jointing, phasing in operations, racking in and out of switchgear, reclosing of electrical switchgear onto a fault, switchgear failure, excavating near live cables or accidental contact with live conductors during maintenance.
1. SKM Systems Analysis
Arc Flash Hazard Calculator
ArcCalc calculates the incident energy and arc flash boundary for any point in a power system be it low, medium or high voltage.
Minimum and maximum arcing short circuit currents are calculated using broad tolerances to provide conservative results with estimated system data.
ArcCalc saves time by automatically determining trip times from the protective device settings. Incident energy, arc flash boundaries and Arc Flash PPE clothing are calculated following the NFPA 70E and IEEE 1584 standards. More information.
SKM Arc Flash Tutorial & Arc Flash Assessment
2. Easy Power
Arc Flash Analysis Software
Easy Power arc flash software provides the most comprehensive productivity configuration for conducting arc flash analysis and ensuring full compliance with OSHA and NFPA 70E requirements.
Whether you’re designing electrical power systems, analyzing arc flash hazards, selecting suitable arc flash clothing or implementing an electrical safety program, this is software configuration can assist. More information – Download Free Demo.
EasyPower Arc Flash Analysis Intro : Automated Power System Design and Analysis
3. Kinetrics 
ARCPRO™ Arc Hazard Assessment, Clothing & PPE Selection
ARCPRO™ has become the industry’s most widely-used application for computing arc hazards and selecting protective clothing for single arc situations, particularly for High Voltage Transmission and Distribution applications not addressed by other methods.
Kinectrics ARCPRO™ calculates the thermal parameters of electrical arcs and is designed to provide users with data regarding heat exposure, total heat flux and heat energy on a surface at various distances from an electric arc.
The software is used to predict the potential arc hazard in a particular work environment and provide basis for specifying the appropriate level of PPE and clothing to protect against arc flash hazards. More information.
Arc Flash Incident (Property of CATU Electrical)
ƒ1 IEEE Std 1584-2002 (Guide for Performing Arc-Flash Hazard Calculations) is a standard of the Institute of Electrical and Electronics Engineers that provides a method of calculating the incident energy of arc flash event – purchase copy of IEEE 1584.
Arc Flash PPE – The Last Line Of Defence
“PPE is the last item on the list when putting in place arc incident control measures. Your arc flash risk assessment should measure the severity of the hazard (incident energy levels) and then look how that incident energy can be minimised. You should then consider what activities you carry out that could expose you to any residual arc flash risk that may be controlled with PPE”, Paul Hopton (Principal Electrical Consultant at Electrical Safety UK Limited).
◊ Can Arc Flash Clothing Save Cable Jointers Lives?
Arc Flash Learning & Resources
Thorne and Derrick are proud to be distributors of ProGARM arc flash coveralls and protection.
We can help – should you require arc flash calculators or advice on the type of clothing and protection available please do not hesitate to contact us.
Electrical Safety UK
ESUK is a specialist company concerned with the safe management of risk associated with all LV & HV electrical work activities. Having pioneered the European approach to Arc Flash Hazard assessment and management, ESUK have a proven track record in ensuring that clients comply with their local law in the most cost effective way.
THORNE & DERRICK are national distributors of LV, MV & HV Cable Installation, Duct Sealing, Jointing & Substation Electrical Safety Equipment – we service UK and global businesses involved in cable installations, cable jointing, substation, overhead line and electrical construction at LV, 11kV, 33kV and EHV.
Since 1985, T&D have established an international reputation based on SERVICE | INTEGRITY | TRUST.
Invitation
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