Having read with interest your health and safety special (EMC, November), I thought it appropriate to highlight another significant safety hazard in our industry.
Let’s not mince words – working with electrical switchgear always involves risks.
Large amounts of energy are continuously available when the switchgear is in use and, under fault conditions, even more energy is likely to be released.
In the unfortunate instance where an operator is exposed to this energy, they are likely to be maimed for life or even killed.
The significant risks associated with switchgear can, however, be controlled to a reduced level if that switchgear is correctly operated and well managed – which involves regular testing, inspection, maintenance, increased user familiarity and updated documentation.
The responsibility for ensuring that these issues are properly addressed falls to Authorised Persons, who will have received appropriate training and be appointed through a lengthy assessment process by their organisation.
But what about older switchgear, especially if it is oil-filled? The small but noticeable amount of rust on the chassis, the mildew in the termination box gasket – do these reflect the condition of the contacts, the operating mechanism, fault containment and the arc dissipating components inside?
Is the operator risking their life when they operate the switch? How do they know whether to operate the switch or not? Is their decision based on guesswork, complacency or faith?
It must be none of these things. The basis for the decision has to be full confidence in an established, properly managed switchgear system, which ensures that the equipment is correctly maintained, considering its age, type and dielectric type, and that any restriction notices have been appraised and appropriate action taken.
Among the most important dangers associated with the use of older switchgear are overstressing (the switchgear may not be rated to handle present-day, full-load currents and fault levels) and dependent manual operating mechanisms.
Anti-reflex handles, which are not often found on older switchgear, are also a prime concern.
Addressing these issues involves implementing an effective switchgear management system.
A very good starting point for this is the guidelines within Health and Safety Executive document HSG230 Keeping Switchgear Safe, which defines clear records that should be kept of the aforementioned points.
Record keeping is not the only requirement. It must be complemented by continued training of persons authorised to operate switchgear.
Care must be taken, however, in selecting the training provider. It is important to choose an organisation that has in-depth knowledge and experience of the special issues involved with older switchgear.
Well-trained personnel and an effective equipment management regime will also result in reduced downtime and increased security of supply.
Investing in health and safety, therefore, is a very sound business proposition.
Marcus Charter ,Power consultant Schneider Electric
Electrical and Mechanical Contractor