• • • TEST & MEASUREMENT • • • Staying ‘ALIVE’ to safe
isolation processes By Steve Dunning, Managing Director of Martindale Electric
T
o safeguard workers and reduce potential liability, electrical engineers must ensure circuits have been de-energised and properly isolated prior to any design, development and maintenance work, explains Dunning. Safe isolation is a vital task which needs to be
performed whenever working on an electrical installation. It ensures both the safety of those working on the installation, and other tradespeople or members of the public who might be on the premises. It is important that the person who performs the isolation is trained, qualified and up to date on the procedures necessary to perform this task. Appropriate equipment is also essential, both testing kit and lock off devices. Electrical Safety First, the UK charity working across the electrical industry reports that injuries caused by electrical accidents are still prevalent, highlighting just how important safe isolation procedures are on site. The Electricity at Work Regulations (EAWR) 1989 and The Management of Health and Safety Regulations at Work Regulations 1999 stipulate the steps those managing electrical work must take to ensure a safe working environment. Before carrying out any work on a circuit, contractors should use a dedicated voltage indicator (VI) and proving unit when proving dead.
The EAWR require those engaged in electrical work to be competent to prevent danger or injury, or to be under the supervision of someone who is (Regulation 16), and to take adequate precautions to prevent electrical equipment that has been made dead from becoming electrically charged while work is being carried out (Regulation 13). They also forbid work on or near a live conductor unless it has been insulated, or it is unreasonable for it to be made dead (Regulation 14). The Management of Health and Safety
Regulations at Work further stipulates that employers must carry out risk assessments prior to such electrical work being done.
Safe isolation and then proving dead sounds like it should be relatively simple. But establishing real confidence around the procedure, so that those carrying out work can do so without fear of harm, requires a rigorous approach to the electrical safety process. Isolation, locking off, proving dead and labelling must be performed in a systematic and methodical manner.
Staying alive We need to acknowledge that, in terms of the safety of individuals, there is a difference between the activities that should take place prior to
working, such as gaining permission and permits, and the activities that are absolutely critical in preventing accidents and fatalities. For instance, a risk assessment is an important element of any job, but that in itself will not keep you alive. The same is true for activities that take place after working on an electrical system, such as safe re-testing and start-up.
Nothing is more important than preventing injuries and protecting lives. Martindale, to ensure the critical steps are memorable, has created ‘A.L.I.V.E’. A.L.I.V.E shines a spotlight on the five vital stages that must be carried out for your own protection and to prevent loss of life.
A.L.I.V.E: 5 fail-proof steps to safe isolation
A - Approved Kit
Before starting, make sure your equipment meets all legal safety standards (for voltage indicators that is BS EN 61243-3).
L - Lock Out Identify the point of isolation, lock it off and place warning tags onto the equipment.
I - Initial Prove Test your Voltage Indicator against the proving unit to make sure it’s working properly.
V - Voltage Test Use your Voltage Indicator to confirm there are no dangerous voltages in the circuit you are about to work on.
E - Ensure Prove the Voltage Indicator against the proving unit again to ensure no damage or fault has occurred before you start working on the circuit.
Prepare yourself
It’s important to choose the right equipment, and a proving unit and lock-off kits should always be available. The point of isolation should be identified, it should be locked off and warning tags placed on all the equipment. A lock-off kit should include, at a minimum, a selection of MCB and breaker locks, a padlock with a unique key, a hasp if more than one person is working on a system and lock-out tags and warning labels. If equipment can be turned off but not isolated, then the person responsible should isolate at the point of connection and then trace the supply back to a point where it can be locked off. Each worker should have their own padlock with a unique key. This is because if equipment is proven dead only for someone else to restore power, the hazard has returned.
48 ELECTRICAL ENGINEERING • MAY 2025
electricalengineeringmagazine.co.uk
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