400V,
No, we do not have to do a written plan, but, it sounds like a GOOD idea!.
Making a reasonable risk assessment, before a job that will encompass Live Work, takes a fair bit of thought, if all of the possibilities(Of What can and May go wrong) are to be taken into account.
Being a worker that works LIVE, pretty much most of the time, here is what I would call a reasonable Assessment:
- What voltage are you working with?
- How can you eliminate any hazards that are nearby, where you are working?.
- What sort of PPE(Personal Protection Equipment), will you need, to do the task without any injuries?.
- Will you require the presence of a Second Competent Person?.
- How can the risk to yourself and anyone else, be minimised, is there a chance that the work can be done at a different time, when the supply CAN be turned off?.
- Have a darn good look around the area where you are about to work, look for any restrictions in your movement or escape paths.
- Figure that you should only be doing LIVE work at the start of a given working day, doing this sort of work when you are tired and cannot concentrate, is just asking for trouble.
- Find out what the PSCC of the installation is, this can have a real influence on the need for extra safety precautions, the arc-flash in two different installations can vary considerably!.
Just a few simple precautions like this can make the difference between a good job and a long stay in hospital.
And another thing is, never work LIVE, without a Fire Extinguisher next to you, CO2, preferably.