549,877 active members*
1,292 visitors online*
Register for free
Login
Results 1 to 8 of 8
  1. #1

    Join Date
    Jun 2018
    Posts
    33

    3-wire toroidal transformer wiring

    I have a toroidal step up step down transformer it only has three wires and a diagram on the side that doesn't mean a lot to me

    this was out of a step-up step-down transformer Pictured below that was working fine 250v in 115v out
    the problem was the American plugs where not solid enough so i my infinite wisdom a pulled it apart as i do with most things.
    but now i cant figure out how to connect it to 220v and get 115v out.

    next time i will leave it alone.

    3000 Watt 110v Transformers, 220V - 110V Voltage Transformer, Step Up and Step Down, UK to US US to UK Trans formator 3000W


    main problem in a nutshell is it only has 2 red wires and 1 black ???

  2. #2
    Registered
    Join Date
    Nov 2012
    Posts
    1170

    Re: 3-wire toroidal transformer wiring

    The input voltage goes between "0" and "220V".
    The output is between "0" and "110V".

  3. #3

    Join Date
    Jun 2018
    Posts
    33

    Re: 3-wire toroidal transformer wiring

    Its ok cheers i have sorted it, its because its a Autotransformer Ha

  4. #4

    Join Date
    Jun 2018
    Posts
    33

    Re: 3-wire toroidal transformer wiring

    you are spot-on cheers i was having a blond moment.

  5. #5
    Registered
    Join Date
    Nov 2012
    Posts
    1170

    Re: 3-wire toroidal transformer wiring

    Happens to the best of us. :wave:

  6. #6
    Community Moderator Al_The_Man's Avatar
    Join Date
    Dec 2003
    Posts
    23820

    Re: 3-wire toroidal transformer wiring

    If you have it connected across NA 240 and use one end to the 120v CT point measure from here to GND to see how much it is above 'zero' .
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

  7. #7
    Registered
    Join Date
    Nov 2012
    Posts
    1170

    Re: 3-wire toroidal transformer wiring

    Quote Originally Posted by Al_The_Man View Post
    If you have it connected across NA 240 and use one end to the 120v CT point measure from here to GND to see how much it is above 'zero' .
    There should be about zero relative to the ground on the "RED 110" wire. 120V above ground on the BLACK wire.

  8. #8
    Community Moderator Al_The_Man's Avatar
    Join Date
    Dec 2003
    Posts
    23820

    Re: 3-wire toroidal transformer wiring

    Quote Originally Posted by CitizenOfDreams View Post
    There should be about zero relative to the ground on the "RED 110" wire. 120V above ground on the BLACK wire.
    Correct.
    The reason I mentioned it is that if feeding any 120v devices or outlets, this should be considered the neutral conductor or terminal.
    CNC, Mechatronics Integration and Custom Machine Design

    “Logic will get you from A to B. Imagination will take you everywhere.”
    Albert E.

Similar Threads

  1. Replies: 21
    Last Post: 10-24-2018, 06:07 PM
  2. Trying to figure out wiring for my DIY CNC - toroidal transformer to 2 phase 240V
    By rickjohnston in forum General CNC Machine Related Electronics
    Replies: 18
    Last Post: 10-19-2017, 08:54 PM
  3. Wiring a dual-coil toroidal transformer...
    By mzungu in forum General CNC Machine Related Electronics
    Replies: 2
    Last Post: 01-24-2008, 02:23 PM
  4. How to wire a toroidal transformer..need advice
    By bgolash in forum General CNC Machine Related Electronics
    Replies: 15
    Last Post: 11-13-2007, 03:22 AM
  5. toroidal transformer
    By cueshark in forum General CNC Machine Related Electronics
    Replies: 1
    Last Post: 05-05-2007, 03:31 AM

Tags for this Thread

Posting Permissions

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