220 Volt Switch


  #1  
Old 03-16-04, 04:53 PM
krawfo
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220 Volt Switch

This is a real basic question and I'm pretty sure I know the answer but I want to be positive.

I'm hooking up a 5hp motor that I wan't to be able to turn off and on with a switch. I found a switch rated at 30 amps. The circuit from the panel has 2 hot leads and a bare ground wire.

Does it matter which hot wire goes to the switch? Should the switch be tied to the ground? ( It doesn't have a ground terminal)
Thanks.
 
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Old 03-16-04, 05:25 PM
R
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You need a double throw switch.

Don't switch just one hot lead. You will be asking for trouble.
 
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Old 03-16-04, 05:38 PM
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***pssst, Bob, double pole ***
 
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Old 03-16-04, 05:56 PM
krawfo
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I'm glad I asked first.
The switch is a double pole and does have a ground. The top of the switch has a brass screw on the right & left side, bottom has a black screw on the right & left with a green screw on the middle of the bottom.
Do the 2 wires leading from the breaker attach to the 2 top (brass) screws and the 2 from the bottom (black) go to the motor? Would the ground wires attach via a pigtail?
Thanks.
 
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Old 03-16-04, 06:01 PM
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You are correct!
 
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Old 03-16-04, 06:05 PM
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That's called not reading before submitting. I started with DPST and then decided to go back and change it. Somehow I lost the middle words. My bad.
 
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Old 03-16-04, 06:09 PM
krawfo
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Wink

Thanks so much for your help!!
 
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Old 03-17-04, 05:45 AM
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Quick question:

When you say you 'found a 30A switch', do you mean that you found one laying around, or that you found a supplier that can sell you one?

If the latter, I'd suggest checking for a horsepower rating for the switch. 30A is probably more than the full load amp rating of your motor, but motors are big inductive loads, with high startup currents (much more than FLA), and switches for large motors should have a horsepower rating in addition to a current rating.

-Jon
 
 

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