I am moving my kitchen temporarily as the builders are propping through the middle of it. I have an ancient neff double oven and it has no info on wattage etc. It currently has an on/off switch to the terminal with the oven cable in. Can I link the oven cable to a 13 amp plug and plug it in (and not use both ovens at the same time) - or get a longer bit of cable and run it 5 metres from the isolator switch as a very temporary measure?