Working with any high voltage system is dangerous; with the right equipment and training, anyone entering these areas is protected at all times and knows exactly what they’re dealing with.
Electricity is all around us on a daily basis. It powers everything from our fridges to our hairdryers and is a convenience that many of us take for granted. It’s also an extremely dangerous property that, when not contained, poses an extreme risk to those around it.
Although it isn’t the level of voltage that causes damage to humans, but rather the flow of current through the body, the risk level of this occurring within a high voltage application increases significantly due to the nature of the equipment within the area and the skills needed to safely interact with it.
Any person entering an HV enclosure should have received a level of training necessary to be competent enough to safely work within this environment. This authorised person may be in charge of a team of individuals with a similar skill set of may instead be a professional who will be carrying out the work.
To promote safety within a high voltage environment and ensure compliance with all rules and regulations, the following guidance (while not exhaustive) must be followed at each and every piece of high voltage equipment that the team will be working on.
- Preparation of a safety programme – this involves a comprehensive inspection and documenting of the problems with an isolation and earthing diagram in duplicate with signature from authorised personnel. The manager in charge of the area must be informed of the work and notices must be placed.
- Isolation and fix signs – All power sources must be isolated from the supply to ensure that the can’t be energised when work is carried. Unauthorised connection should be stopped by fixing safety locks and caution signs at isolation points (lockout tagout) and danger signs must be placed to warn those around of the nature of the high voltage work
- Prove dead – Use a high voltage potential indicator at all isolation points and also prove low voltage transformers, pillar and distribution boards are not energised
- Earth – Conductors must be safely earthed and locked to prevent access. Identification with certainty or spike underground cables at the points of work if the conductors are to be cut of exposed. Overhead lines near to the work environment must also be earthed.
- Issue Permit-to-Work – A competent person must be shown the safety arrangements at all isolation points and work locations. This person must initial the isolation and earth diagram, the point of work must be marked and the permit-to-work, isolation and earthing diagram and the key to the safety box must be given to the competent person. The mimic diagram must be adjusted and the site logbook must be completed.
Only at this point should work go ahead on high voltage systems. By performing these tasks ahead of time, those working with these potentially dangerous systems are protected at all times and can be confident that responsible people are monitoring their work.
Of course this is only a brief guide to working safely within an HV environment; after work is completed there must be additional work carried out to check the safety of equipment and restore the operational state, while those working with the system must have access to the correct equipment and training to work safely in these areas.
To learn more about how you can work safely in a high voltage environment, visit our high voltage training courses page.
