I'm fairly certain that a hazardous voltage is defined as anything over 50 volts. Lindsay's assertion that live working will be "virtually nill" is most certainly not true in our workshop ! Most modern equipment has fully protected mains input terminals and transformer connections - but if there's a switch mode power supply the mains (and worse) is present on a PCB - and most old equipment relies on a warning notice on the case or on internal chasis panels.
There has been at least one EBME workshop closed down by the H&S inspector because of lack of adequate precautions against electric shock. Quite apart from that risk - isn't it better to be safe - just in case ? How much does a ELCB cost ? Not a lot !
