HSE Electrical Inspectors. Employed in a variety of operating directorates: –
Hazardous Installations Directorate (HID). – Nuclear Safety Directorate (NSD).
Health Healthand andSafety Safety Executive Executive
LOCAL AUTHORITY HEALTH AND SAFETY TRAINING Electrical Safety – Case Studies Andrew Pitt Field Operations Directorate Electrical & Control Systems Engineering Section 1 Hagley Road Birmingham B16 8HS 0121 607 6286
[email protected]
OVERVIEW To provide local authority inspectors and support staff with increased awareness of electrical hazards and risks to help you improve safety in the workplace Today’s presentation will cover: – – – – – –
HSE Inspectors Electricity at Work Regulations Electrical Danger Equipment in Buildings Appliances Case Study
HSE Electrical Inspectors Employed in a variety of operating directorates: – Hazardous Installations Directorate (HID) – Nuclear Safety Directorate (NSD) – Field Operations Directorate (FOD) – FOD deal with the majority of industries and provide technical support to other Directorates and to Local Authorities
HSE Electrical Inspectors Inspectors are Chartered Engineers who have a range of industrial experiences. We do the following: – Inspect electrical and control systems. – Investigate incidents and dangerous occurrences. – Provide specialist evidence in legal proceedings and Coroner’s inquests. – Provide guidance (in very many forms). Although we are seen as enforcers, we also offer assistance and support, from advice to joint visits and reports.
HSE Electrical Inspectors The Y & NE, Midlands, London, E & SE team consists of 4 electrical inspectors managed by a principal inspector based in Leeds Two Inspectors in Birmingham – Andrew Pitt and Paul Mursell An inspector in Norwich – Richard Hines An Inspector and Principal Inspector in Leeds – Mark Gough and Ian Burley
Electricity at Work Regulations 1989 Regulation 4 Construction Maintenance Systems of Work Suitable Safety Equipment Regulation 6 Adverse Environments Regulation 14 Work near Live Conductors
BS7671:2008 The Wiring Regulations Published by the Institution of Engineering and Technology (IET) formally the IEE. Currently in their 17th Edition Although called Regulations, this is a British Standard and has the legal status of guidance. The requirements of the regulations are not retrospective. The requirements of the regulations are not directly enforceable
Electrical Danger In the Electricity at Work Regulations, Danger means the risk of Death or Injury from: – Electric Shock – Electric Burn – Fires of an Electrical Origin – Electric Arcing or Explosion
Fibrillation of the heart
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Electric current above approximately 50 milliamps can cause the heart to stop beating normally
• • •
Heart flutters – unable to pump blood Lack of oxygen to the brain leads to death Heart has a vulnerable period in normal cycle
Triggering of ventricular fibrillation in the vulnerable period. Effects on electrocardiogram and blood pressure R
R Ventricular fibrillation
ECG
T
P
P
Q S
Q
S
120
Blood-pressure
80 mm H9 400 ms
40 0
Shock Currents at 50Hz
Effects of current on the body Milliamps 0.5 - 2
Threshold of perception - no ill effects.
2 - 10
Mild to painful shock
10 - 20
Severe shock - Muscular contraction and some paralysis "UNABLE TO LET GO"
20 - 100
Very severe shock. Muscular contraction and paralysis, loss of consciousness and one of the following: "a" Breathing and pulse continues "b" No breathing - pulse continues "c" No breathing - no pulse
Over 100
Fatal shock, ventricular fibrillation occurs, burns at point of contact. DEATH ensues through lack of oxygenated blood supply to the brain in 3 - 7 minutes.
Summary
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Electricity very dangerous
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Shock at wrong time in heart cycle can trigger fibrillation
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230 volts a.c. dangerous – many electrocutions occur at this voltage
>50 v a.c. and >120 v d.c. can in some conditions be potentially fatal
Electrical Equipment in Buildings
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Distribution Network Operators Cut Out The point at which the electricity companies equipment ends and the duty holders responsibilities start
Electrical Equipment in Buildings
Consumer Unit
Distribution Board
Electrical Equipment in Buildings Consumer unit with front cover missing. Exposed live parts Risk of electrocution
Electrical Equipment in Buildings Circuit breaker distribution board with front cover open. Exposed live parts Risk of electrocution
Electrical Equipment 4 way extension lead Broken Casing Exposed live parts Risk of electrocution But is it dangerous?
Electrical Equipment Found hanging by flex being used to charge a phone Wires held in by another appliance. No earth connection
Multi way Adaptor
Broken body. Potentially exposed live parts But is it dangerous?
Outdoor Distribution Equipment
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Industrial type sockets and plugs.
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Suitable for use outdoors
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But not with missing bung in the top of the unit!
Cable Connections Chocolate block connectors should raise concern when ever they are found.
Electrical Equipment Chaffing Dish Heater. Hotel Breakfast Buffet Member of catering staff received an electric shock
Is this Safe?
Is this Safe?
Explosion at a Cafe Electrical cupboard back in use after explosion
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Damage to cut out
Case Study
An employee sustained an electric shock and burns to her hand whilst opening a window through which an extension cable passed. This cable was being used to supply a television set located within a staff restaurant area from a double socket outlet in a Firm pleaded guilty to charge brought by segregated smoking area.
LA under EaW Reg7 and awarded £10K fine plus full costs
Defects identified at the flexible cable were consistent with damage sustained by trapping and cutting from,sharp edges similar to those identified at the aluminium section window frames in both the smoking area and restaurant.
Thank You Any Questions
