Page 1 of 2 12 LastLast
Results 1 to 10 of 15

Thread: Electrical question - 220v

  1. #1
    Join Date
    Feb 2008
    Location
    East Freeetown, Massachusetts
    Posts
    3,022

    Electrical question - 220v

    If I have a device that is 220v I need a switch to turn it on and off.

    The 220v circuit is 2 hot wires - really nothing else is needed. A ground is a nice to have, and I will ground.

    Do I need to break both hot leads? I think I should break both. In a 110v I need to only break only one lead.

    Sooo, on a 220v circuit, what does a switch look like, assuming relatively low amperage (2a) What does a switch look like for 15a
    Is this a double pole single throw switch (DPST)?

    Can you post links to Amazon possible switches for those 220v circuits?

  2. #2
    Join Date
    Dec 2006
    Location
    Independence, Kentucky
    Posts
    1,355
    Leo, you have it right DPST is what you want, Carling makes a very good switch , a little more costly, but a good product.
    https://www.amazon.com/s/ref=nb_sb_s...ST%2Caps%2C144
    I'm supposed to respect my elders, but its getting harder and harder for me to find one now.

  3. #3
    Join Date
    May 2007
    Location
    Kansas City, Missouri
    Posts
    13,452
    Correct, break both leads using a DPST switch. Looks like Charles has you hooked up on the link.
    Darren

    To a small child, the perfect granddad is unafraid of big dogs and fierce storms but absolutely terrified of the word “boo.” – Robert Brault

  4. #4
    Join Date
    Aug 2007
    Location
    Reno NV
    Posts
    13,361
    If you want to live on the edge, you could get one of these "safety" switches

    Click image for larger version. 

Name:	713YUOumlmL._SL1100_.jpg 
Views:	15 
Size:	54.4 KB 
ID:	97083
    Programmer - An organism that turns coffee into software.
    If all your friends are exactly like you, What an un-interesting life it must be.
    "A door is what a dog is perpetually on the wrong side of" Ogden Nash


  5. #5
    Join Date
    Jul 2011
    Location
    The Gorge Area, Oregon
    Posts
    4,699
    You can also get wall switches
    https://www.amazon.com/Leviton-CS220.../dp/B000U39UC6
    https://www.amazon.com/Leviton-MS302.../dp/B002MPQ51O

    Push button switches
    https://www.amazon.com/Woodstock-D41.../dp/B005W17GZE

    Paddle switches
    https://www.amazon.com/Woodstock-D41.../dp/B005W17FRS

    The reason you want double pole is that in a 110v circuit only one "leg" is hot - so if you interrupt that leg you can't complete the circuit with either the neutral or the grounding wires. You also want to interrupt the hot leg in that case, if you find a switch that is switching on the neutral its a hazard condition because the circuit is still energized and needs to be fixed asap. With 220 both wires are hot, so you can complete the circuit from either of them to either a grounding wire or to the earth itself (because that shares a common ground). This is also why its a BAD IDEA to do things like wire together two 110v switches or breakers, because if one trips and the other doesn't the load can all go through the untripped side overload the rest of the circuitry (i.e. the wire) quicker than the breaker can trip causing a flash and thus a fire.
    Love thy neighbor, yet pull down not thy hedge.

  6. #6
    Join Date
    Jul 2011
    Location
    The Gorge Area, Oregon
    Posts
    4,699
    Quote Originally Posted by Brent Dowell View Post
    If you want to live on the edge, you could get one of these "safety" switches

    Click image for larger version. 

Name:	713YUOumlmL._SL1100_.jpg 
Views:	15 
Size:	54.4 KB 
ID:	97083
    Aww, that's fine looking. Be sure to throw those with verve so they aren't left doing the arky sparky dance. I've welded a couple of those shut by being hesitant
    Love thy neighbor, yet pull down not thy hedge.

  7. #7
    Join Date
    Feb 2008
    Location
    East Freeetown, Massachusetts
    Posts
    3,022
    FANTASTIC - Great suggestions.

    I know what to do now

  8. #8
    Join Date
    Feb 2008
    Location
    East Freeetown, Massachusetts
    Posts
    3,022
    Quote Originally Posted by Brent Dowell View Post
    If you want to live on the edge, you could get one of these "safety" switches

    Click image for larger version. 

Name:	713YUOumlmL._SL1100_.jpg 
Views:	15 
Size:	54.4 KB 
ID:	97083

    Ahhhh YES - Double Pole Single Throw.

    This is what I had in mind.

  9. #9
    Join Date
    Jul 2011
    Location
    The Gorge Area, Oregon
    Posts
    4,699
    One thing to consider (based on the type of equipment you're using)... is a magnetic interlock switch. Basically they will shut off if the power is disconnected and NOT turn back on if the power comes back. They are substantially more expensive though. I don't know your use case here, but it might be a consideration depending on the possible projected failure modes....

    For example:
    http://www.grizzly.com/products/Magn...campaign=zPage
    http://woodworker.com/1hp-5-8amp-1ph...su-923-950.asp

    Grizzly has a nice selection of switches overall..
    http://www.grizzly.com/search?q=(categoryid:275010)

    If you're looking for a more central maintenance disconnect something like this
    http://www.homedepot.com/p/GE-60-Amp...0RCP/100674085
    actually works pretty well.. It would be used if you have an piece of equipment that you want to completely cut _all_ power to for infrequent periodic maintenance (commonly things like hard wired air compressors or dust collectors). The nice thing about this sort of disconnect is that you can LOCK the disconnect so no one can re-energize it without removing your lock (common practice in industrial settings - search "lock out tag out" for more). I wouldn't use it for something you needed to disconnect more than say monthly as the interface isn't really rated for a high duty cycle.
    Love thy neighbor, yet pull down not thy hedge.

  10. #10
    Join Date
    May 2007
    Location
    Thomasville, GA
    Posts
    5,998
    I've used this switch on several tools for about three years. They work great!
    Bill Arnold
    Citizen of Texas residing in Georgia.
    NRA Life Member and Member of Mensa
    My Weather Underground station

Similar Threads

  1. Electrical Question
    By Michael Tulak in forum Off Topic Discussion
    Replies: 9
    Last Post: 05-04-2015, 08:55 PM
  2. Electrical Question
    By Sayer Fancher in forum Off Topic Discussion
    Replies: 11
    Last Post: 12-13-2014, 06:17 PM
  3. An RV Electrical Question
    By Paul Douglass in forum Off Topic Discussion
    Replies: 17
    Last Post: 04-29-2014, 08:33 PM
  4. Cutting blanks on Bandsaw - 220v wiring help / question ?
    By Dan Mosley in forum General Woodturning Q&A
    Replies: 10
    Last Post: 11-04-2012, 02:11 AM
  5. Electrical question
    By Bob Gibson in forum Off Topic Discussion
    Replies: 9
    Last Post: 08-27-2011, 03:30 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •