Motor Starter Wiring

A word of warning: 440VAC arcs are *not* self-extinguishing. They can turn into very dangerous explosions. Do not use any kind of switch, contactor, or disconnector for 440 that is not labeled for that use. Don't use cords and plugs: hardwire everything and put it in conduit.
 
Thanks for the info. Yes it will be hard wired for sure.

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Here's the diagram:
 

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dcheff said:
I too know Jim is correct. If you don't have useful information stay out of the thread. I will do this myself as I do everything myself. I know its dangerous that's why I am looking for information. I am basically looking for a wiring schematic so I can change this to what I need, yes it will be a separate control circuit at a lower voltage. I'm sorry I'm not afraid of doing things myself like most of you seem to be but I look at things like this as learning opportunities, I don't get scared and hire a pro.

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I have been successful at downloading wiring diagrams that would be very helpful from the Square D web site. They are quite extensive and cover most industrial power and control circuits. They start with standard symbols and progress to more involved circuits.
 
jim18655 said:
Here's the diagram:
Click to expand...

I didn't see this download before I posted the Square D website suggestion. This looks like it's from that site. If I am understanding your situation correctly, that is that you are only changing out the motor to 480 VAC, than the addition of a control transformer will be necessary for your application. You would insert it between the 2 480 VAC lines supplying the circuit with the push buttons and contactor coils which are probably 240 VAC. The overload change out suggestions will also apply.
 
Yes Uncle Harry, I am not sure if I am going to use a transformer, I like the kiss method, keep it simple and with the least amount of parts should keep it the most reliable. Therefore I think I am going to change out the coils so that the control circuit is 480v also. I will know better after this weekend, I am actually having to do some work right now so I cant work on the lathe just yet. But I am hoping the diagram from jim should be enough to get me rolling on this.
 
dcheff said:
Yes Uncle Harry, I am not sure if I am going to use a transformer, I like the kiss method, keep it simple and with the least amount of parts should keep it the most reliable. Therefore I think I am going to change out the coils so that the control circuit is 480v also. I will know better after this weekend, I am actually having to do some work right now so I cant work on the lathe just yet. But I am hoping the diagram from jim should be enough to get me rolling on this.
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I strongly suggest that you use a transformer. Lowering the control voltage to 120 will increase reliability more than adding a lump of iron and copper will decrease it.
 
Ok why is that John? Is it really dangerous to have the coils be 480v? I believe everything I have is rated for it besides the overloads and coils (but I will change them out). I am listening, i guess I just do not know why it is a bad idea to go to 480v.
 
dcheff said:
Ok why is that John? Is it really dangerous to have the coils be 480v? I believe everything I have is rated for it besides the overloads and coils (but I will change them out). I am listening, i guess I just do not know why it is a bad idea to go to 480v.
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Lower voltage means less stress on insulation, less arcing and resulting wear when contacts open, and less damage should a fault occur. 120 components are also less expensive and more readily available.
 
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