Have recently been asked the question if a convertor can be used on construction sites to convert a 240v appliance to 110v therefore allowing it to be plugged into a 110v transformer. I am a little unsure how the 240v machine would work, powered by a 110v transformer. Apparently on another site this is acceptable. Is the potential shock value still 55v through either arm. Is it legal on sites. The scenario is a transformer plugged into a 240v socket, an adaption lead plugged into the transformer with a male end , and on the other end is a 240v female socket to accept the appliance. Any inputs welcome.

Electrically, it's possible. I wouldn't do it, though, because it's rather defeating the point of 110V centre-tapped power on construction sites. If you're going to do what you propose you may as well just plug the appliance straight into the 240V socket you start with. The shock you will get from the appliance will be 240V whether it has converted from 240 to 110-c-t and back to 240 or not.

Depends on the machine, it might have a power sply that accepta varying voltage. We used to provide anti condensation heaters to control panels we purchased. The panels would sitin green kiosks that would be factory fitted with lights and heaters to run on 230 vac. During construction we supplied the resistive heaters with 110 volt, it simply reduced the power output. It was a safe and simple use and meant we didnt have to run 'proper' supplies out across site. Ask the manufacturer would be my advise