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Wiring a bench grinder toggle switch

curlysnipe

Member
Joined
Apr 27, 2023
Messages
15
I have a Millers Falls bench grinder that I restored. The plug cable was dried out and had exposed wiring. I replaced the toggle switch and the plug cord. I should have taken a photo to remember how the toggle switch and plug cord were wired. I placed the cord black lead (hot) to the motor wire with the red tip and attached them to one pole of the toggle switch. I placed the cord white lead (neutral) to the motor wires with the white lead and attached them to the other pole of the toggle switch. Everything grounded, I plugged the grinder to an extension cord that has an on an off switch. When I flipped the switch on the extension cord the bench grinder immediately started working just fine without me having flipped the toggle switch on the bench grinder to the on position. So I flipped the toggle switch on the grinder the other way and immediately my panel breaker overloaded and flipped to off. I assumed I must have inadvertently direct wired or hot wired the bench grinder. I flipped black and white on the connections and still it behaved the same. I'm scratching my head. Can someone out there tell me what I am doing wrong by looking at the photos I uploaded?
 

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curlysnipe

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Joined
Apr 27, 2023
Messages
15
Thank you for the response. I'm not clear on what you are trying to get me to do. I should switch the hot lead but to where? All the neutrals I should just wire nut together, correct?
 

American Locomotive

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Jan 8, 2017
Messages
11,130
Location
Rhode Island
Think logically about what you did. Forget the switch for a second. You tied the black wire directly to the red motor lead. You then tied your white wire directly to the neutral motor lead. You have just directly wired the motor to the cord. If you think about it, it's rather obvious the grinder will have no choice but to run.

...then you ran a connection from hot to the switch, and a connection from neutral to the switch. That's a direct short once the switch is on.

You only need to switch the hot lead. So the black wire from the cord goes to one side of the switch, the red wire goes to the other side.

The white wire from the cord just goes directly to the other neutral wires.
 
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curlysnipe

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Joined
Apr 27, 2023
Messages
15
Thank you everyone.
American Locomotive, I did exactly as you said and of course it worked. You were right. I had to think of it in terms of where am I was sending the current to and how it was travelling full circle. I kind of laughed at my mistake once I read your response. Thank you so very much.
 

exmaxima1

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Joined
Jun 25, 2011
Messages
6,351
Location
Midwest
I just finished putting a new cord and switch in the same type grinder (also made by Kingston-Conley) so I'll post a pic to confirm the correct wiring.
 

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