I recently fitted an old (I guess late 60s), heavy, cast iron cased William Allday & Co Starter Regulator as a speed control for my fan blower. I had a friend who is an electrician check it over beforehand and he gave it the all-clear; he also went over the wiring connecting it to the blower, all is well there. But… I was forging yesterday and while waiting for a heat I happened touch the casing of this regulator, it was pretty hot; of course, there must be resistors in it so I’d expect a temperature. But, how hot is normal, is touchable alright or is there a problem I need to solve? Thanks in advance for help. G.

Speed controllers that I know about use a coil of wire that electricity passes through..as it does that the coil heats up and that lessens the amount of current it will flow.

i do not know if that is the kind you have..also you did not mention wot kind of blower you use. I think they have to match each other and the motor has to be able to be used with the kind of one you have.

So with all of that It almost seems like i would not be happy with a controller as hot as youi say yours is..And if it is to hot it likely will not last long...I would take both pieces to a electric motor rebuilding shop and have then check it out.