Electrical Hazards – why HV Training is necessary

20 May 2016


Electricity kills and severely injures people every year, as well as causing damage to property from the resulting fires and explosions. But what are the hazards? And why is training necessary?

The main hazards

Electric shock/burns through contact with live parts

What many people don’t realise is the human body is a very good conductor of electricity; after all, we are made up of 70% water. This causes serious issues if we do receive a shock. An electrical current flowing through a body heats up body tissue as it passes through, just like a light-bulb filament, causing deep and incurable burns.

A large shock can also interfere with the electrical functions of the nervous and muscular systems, and in serious cases, can cause instant heart stoppage. The standard 110V found in households is enough to cause serious damage. The effects of electricity will be felt immediately, so most people will not have time to pull away. If the electricity is strong enough it will cause the victims muscles to tighten so they can’t let go.

Arcing, fire and explosions due to faulty electrical equipment or installations

Faulty equipment can cause an arc flash, these occur when electric current flows between an air gap between conductors. A flash generates a large amount of heat that can burn human skin and set clothing on fire instantly and temperatures at the arc can be four times the temperature of the Sun’s surface! Similarly, faulty equipment can create sparks that create quick-spreading fires.

A sudden release of energy can cause an explosion; this can be due to faulty equipment or incorrect working methods. We recently shared a shocking video captured in London that shows an electrical explosion caused by a worker accidentally hitting a 11,000V cable with a jackhammer, you can read the full story here.

What you should do

A suitable risk assessment should always be taken, taking into consideration the type of equipment to be used, the way it will be used, and the environment it will be used in. All electrical risk assessments should cover the following areas:

  • Who could be harmed
  • How the level of risk has been established
  • The precautions taken to control the risks

You must ensure that all electrical equipment is suitable for its intended use and the environment where it is to be operated and only used for its intended purpose. You must also ensure that all electrical equipment and installations are maintained to a level where danger can be prevented.

Key training points

  • Ensure a risk assessment is completed for all work that is planned
  • Make sure all staff are trained to recognise all types of electrical wires. These can range from large overhead power lines, to small electrical wiring in a workplace, or difficult cables buried under the ground
  • Source an up-to-date map of all electrical services in the area
  • Scout the area where you are going to work and look for any signs of electrical wires, cables or equipment. Remember to look up, down, and around you
  • Use a cable locator if you intend to dig or disturb the earth, clearly and permanently mark the position of services you do find
  • Work away from electrical wiring wherever possible
  • Make sure the power is off, and cannot be turned on again without you agreeing
  • Put up danger notices and warn any colleagues where is safe, and isn’t safe to work

Our courses

Develop Training Ltd’s (DTL) courses are ideal for Competent Persons, Authorised Persons, Engineers and Managers, with responsibility for Electrical High Voltage and Low Voltage systems. Our courses reflect the latest methods, practices and legislation and provide hands-on experience on specialist equipment.

Our experienced teams can also provide consultancy on safe systems of work and create bespoke programmes aligned to business procedures. Courses are suitable for all commercial sectors, as well as healthcare, including the National Health Service and, the Ministry of Defence.

DTL offers a large range of electrical courses for people of all skill-sets. Click here to see our range of courses. Alternatively, call our team on 0800 876 6708.