Hi, I need to rewire a Leitz Focomat 11C. The wires in this are before the days of polarized plugs so this maching has only a two prong plug to go into the wall outlet. Once i exposed the wires in the actual lamp housing I can that is has three wires, white, black and red. The red is the ground because it is connected to the outter case of the lamp house. First thing: The white wire goes to the center of the lanp, Usually the black is the hot wire and one would think that it should be going to the center. Second: why would they have a ground wire (red in this case) if the whole maching only has a two prong plug for the wall? The cord that goes from the enlarger to the wall outlet looks original as does the plug on it. I can get new wire and just replace them one at a time until the whole thing is rewired just like it is now, but doesn't that make the enlarger outside subject to getting electrically hot if a wire ever thouches the metal? and why the red ground wire if only a two prong plug? thanks for your help.