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Peppie

5 hp motor switch??

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Looking for a switch for a 5hp 1ph 230v electric motor. Would like the switch to have an emergency paddle off button.  There seems to be many different ratings on these types of switches. I dont have a clue on which will work.

And is there a supplier that offers this "on-off" switch mounted in a metal box? Can't seam to find said item, after a lengthy search on line.

Hhhhhhhhhhelllllllpppp. Please

Peppie

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forget box stores, try electrical supply houses like All Phase or Kirby Risk your local brand and mileage will vary

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You need one rated at 30 amp or more. Pretty common in industrial electrical suppliers down here. 

You can also buy a contactor and have it in a box. The contactor can be operated with any ordinary switch located anywhere you want, and can be toggle, lever, etc. 

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A single phase 230 VAC, 5 HP draws 28 amps.  30 amps would work but be tight.  I would opt for a 35 Amp switch.

The other option mentioned is a starter - you will need a NEMA size 2 for the motor, pretty standard - just search the web.  NEMA size 2 is designed to handle a motor up to 7.5 HP.

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Considering that you guys don't have 230V but 220V at the best of times, I would go for 35 and up, See what's available in the electrical supplies shop. Contactors or starters like you call them are not expensive and are great for remote starting, that is when the switch is some distance from the motor. 

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Peppie: When you consider advice you read here or heck anywhere you have to consider the source. In this case, a LICENSED professional electrician, cut and paste pages from a book or someone living in a different country who doesn't know what voltages we run here. 

This much power isn't the place to bet your life on some guy on the internet. Better still hire someone licensed and bonded and have it done right. 

Frosty The Lucky.

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Available voltage in the USA is 240 actually,  varies down to 225 volts.  Sad that someone is posting 30 amp then changes to 35, and now the voltage thing :( people that don't know the answer should not guess and let those of us that do know, answer the question

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Thanks for the responses. 

I do take Everything I read on the net with a grain of salt.

Thru my own research ( and consulting with an electrician  friend)on some of the products listed above, I feel the best option  for my situation will be the contractor.(DOL) It will be rated for 7.5 hp. It will run in conjunction with a 35amp on off switch.

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1 hour ago, Frosty said:

This much power isn't the place to bet your life on some guy on the internet. 

I agree - after 25 years as an Electrical Engineer doing power distribution in buildings - I don't trust myself all the time either....  :rolleyes:

As I always tell everyone that asks for advise and is not comfortable working with electricity - call an Electrician - cheaper than a house fire.

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Actually I'd consider a house fire to be a relatively minor issue; you see we bought our first house from the widow of a telephone company central office maintenance man who electrocuted himself working on fixing a problem in the kitchen.  Left a wife and two young kids and a beautifully wired shop...

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Please listen to Steve. The code requires conductors and equipment to inductive loads to be sized at 125% of operating current.  It's not always as simple as reading a nameplate or a chart somewhere.  This is because many motors draw huge starting (inrush) currents before they reach synchronous speed. Contactors that aren't properly selected, or set up will only work for a while.  I've replaced contactors that were welded in the on position, and I've replaced others that were burnt in two.   Purpose-built motor starters combine the appropriate contactor with an overload relay.  They are often sized by the motor's horsepower but you have to be very careful not to stumble into a 3-phase motor starter since those are much more common.  

Finally, I think it's really, really, important to point out that electrical equipment voltage ratings are nominal.  The actual supplied voltage is always different than the system name would suggest.  Devices properly rated for an installation might sport any of the following ratings; 210V, 220V, 225V, 230V, 240V, or 250V.  "Intelligent" devices might have labels that read 100V~250V which means the device can accept a range of voltages.  None of this stuff is made for installation by unqualified personnel so the installation instructions/schematics tend to be pretty minimalist.

 

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there are good reasons its a 5 year apprenticeship to become an electrician, not just for collecting training fees.   Also starters are commonly uninstalled at the motor.

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