Electrical contractors and maintenance engineers are often working in commercial properties or industrial settings where there are lots of other people and other operations present. In many cases these operations need to continue running while maintenance work or electrical testing takes place. It is therefore necessary to isolate a specific circuit or piece of equipment and shut it down in order to do this, but a fundamental safety mechanism needs to be in place to prevent that circuit or piece of equipment being tampered with and/or started up again. And this is where the lock-off kit is an essential element of the safety mechanisms used by electrical testing personnel.
So a lock-off kit is a comprehensive range of lock-off devices which can be attached to the primary isolating point of electrical equipment. This is quite often a distribution board or an electrical panel, but can also be a specific component within a panel, such as a mechanical circuit breaker, a residual current circuit breaker or a fuse holder. The range of lock-off devices can range from a simple tag that gives a visual warning not to touch or change the isolation point, to a padlock designed to physically prevent a person accessing an isolation point.
How to decide what kind of lock-off kit you need
The type of lock-off device used is at the discretion of the user, but should be decided upon as a result of a comprehensive risk assessment, which breaks down the task in terms of the risks and hazards involved, the control measures in place, and concludes with what type of isolation device is necessary. Where the risk is minimal and only low voltages are concerned, it may be considered that a simple warning tag is sufficient communication of the possible danger. But where larger voltages are involved and the risks are much higher, it would be recommended to use a hasp or padlock to physically prevent an isolating switch from being accidentally activated.
So a lock-off kit is a means of communicating the fact that a circuit or piece of equipment has been powered off and isolated, and in some cases is a physical barrier to accessing the isolation point, and it should remain in place until a testing or maintenance task has been completed. Hence, whichever lock-off device has been agreed upon, it should be sufficient to remain in place until the circuit or piece of equipment is ready to be operational, and therefore is safe to be removed from an isolation status.
What is contained in a lock-off kit?
Lock-off kits can vary in size, but some premium quality kits, such as the TIS PKIT Professional Lock-Off Kit supplied by Test Instrument Solutions, comprise of a comprehensive range of lock-off devices for all possible isolation requirements. This includes various locks, hasps, keys and tags to cover the range of equipment commonly found in commercial and industrial settings. This should suit the requirements of most electrical testing engineers and maintenance contractors, and includes locks for specific equipment and components, such as circuit breakers and fuse holders, and other lock-off devices with universal purposes.