I have a job to replace a motor starter that was bad, an old Allis Chalmers. I go to install it and there are two wires that are on a set of N/C contacts. When I go to put the new Sq. D starter up I'm thinking where should these wires go. The only N/C contacts on the new Sq.D are the overload contacts for the coil. So happens that there is another Sq.D starter that works in conjunction with this one. They operate 2 air compressors outside. On the existing Sq.D starter, (after a few mistakes on my own), I notice that they have taken the wires to the coil off the overload contacts, and used these contacts for the other two wires, which are coming off of the pressure switches. Isn't this defeating the purpose of the overload for the coil? I don't do a lot of starter wiring, but can't you buy an extra set of N/C contacts that can be added to this starter? It is a Size 1, 3 phase, with a 460 volt coil. I didn't see a place to install another set of contacts, but it seems that I have run into it in the pass somewhere. I'm thinking this is rather dangerous for the compressor. In the event that one of the heaters blow, won't the compressor keep on running on single phase and burn the compressor up possibly without the overload hooked up? I know I'm missing something here. Like I said, I don't do a lot of starter wiring. Thanks for the input. Steve
