You can't see it, smell it or hear it - when working with electricity you need extra precautions in place to ensure employees and contractors aren't exposed to potentially lethal live circuits.
The established best practice is to safely isolate any live electrical circuits using a locking-off kit. There are a number of kits available on the market, however a basic package should include the following:
Padlock with a unique key or combination
Hasp for when more than one person is working on a system
Lock out tags & warning labels
Note that the padlock must have a unique key or combination held by the person carrying out the work to prevent anyone else from removing the lock and inadvertently activating the circuit. Most combination padlocks have a default setting of zeroes, so if you are using this type of lock, ensure the combination has been changed prior to use. Using an appropriate MCB and breaker lock, the live feed should be locked down correctly and a warning tag attached to clearly identify that the circuit has been locked off and is currently being worked on.
SG World's LotoTM comprises a multi-purpose tag and register which houses specific job details and responsible contact information both as a central record and at point of use. Circuits are frequently mis-labelled so there is no certainty that the correct circuit is locked off and some capacitive systems hold electrical charge. To verify this, you should use a dedicated voltage indicator and a proving unit. A supporting isolation certificate has the dual function of identifying the isolated equipment before carrying out any work on the circuit and ensuring the area is made safe and clean prior to power being re-connected.LotoTM also includes magnetic warning signs to highlight the Lock Out Tag Out status for large equipment where the power switch isn't clearly visible.
The additional information recorded on the tag is also retained in theLotoTM register giving the Health & Safety manager and external/internal auditors access to important information about past jobs, such as frequency and time taken. This record can help improve maintenance planning going forward and identify any recurring issues as well as evidence a track record of best practice. LotoTM centralises Lock Out Tag Out into a formal, auditable process, clearly identifying job specifics and responsible personnel. The visibility of any on-site Lock Out Tag Out activity is increased and the tick-box based work instruction means everyone can easily follow the same robust safety procedure.