I fitted a fluorescent strip light today purchased from B&Q. I'm a bit confused because there is no earth point anywhere on the unit. It's powdercoated metal casing, so i assume it needs earthing, but there is no earth on the terminal block or anywhere else. The instructions say that it needs an earth, but i suspect these are generic to quite a few different light fittings. Am i right or are these units now double insulated and don't need one?