Results 1 to 7 of 7

Thread: Blew up CT312 welder today! Help with wiring

  1. #1
    Join Date
    Oct 2018
    Posts
    17
    Post Thanks / Like

    Blew up CT312 welder today! Help with wiring

    Hi everyone - so I have owned this little cheapo 3-in-1 welder for 3 years now. Its worked ok but on 110 theres only so much one can do. Wired it up for 230v today and blew a cap / smoke pouring out of the thing-

    Specs says 110+230v https://gnktools.com/catalog/manual/ct520d.pdf

    So.. I hooked up the 2 hot leads to each of the 110v wires (black and white basically) -

    I had to convert from a 4 pin 230v generator plug to a 3 wire 110v (came with the welder) - like the pic-

    Was i an idiot?

    Name:  welder-wiring.jpg
Views: 150
Size:  68.7 KB
    Last edited by SavedInChrist; 03-05-2021 at 09:55 PM.

  2. #2
    Join Date
    Jun 2012
    Location
    Laredo, Tx
    Posts
    5,545
    Post Thanks / Like

    Re: Blew up CT312 welder today! Help with wiring

    Maybe. Did you verify Line1 & Line2 had 240V between them, and each one to ground had 120V?
    1st on WeldingWeb to have a scrolling sig!

    HTP Invertig 400
    HTP Invertig 221
    HTP ProPulse 300
    HTP ProPulse 200 x2
    HTP ProPulse 220MTS
    HTP Inverarc 200TLP
    HTP Microcut 875SC

  3. #3
    Join Date
    May 2010
    Location
    ct.
    Posts
    1,285
    Post Thanks / Like

    Re: Blew up CT312 welder today! Help with wiring

    Or maybe the manufacturer neglected to tell you
    there’s a jumper inside the machine that needs to
    be moved for 240v. operation?
    Miller a/c-d/c Thunderbolt XL
    Millermatic 180
    Purox O/A
    Smith Littletorch O/A
    Hobart Champion Elite

  4. #4
    Join Date
    Oct 2018
    Posts
    17
    Post Thanks / Like

    Re: Blew up CT312 welder today! Help with wiring

    verified 240v yes .. (was still cycling down to 230v, i measured it right at start) -
    Looked inside - no jumper. Im going to replace the blown cap and try again on 110v, try and resurrect it - everything else looks ok (no burns/etc)

  5. #5
    Join Date
    Mar 2010
    Location
    Ceres, California
    Posts
    3,819
    Post Thanks / Like

    Re: Blew up CT312 welder today! Help with wiring

    If this welder is a 115 / 230 volt welder. there should be some way to adapt to the different line voltages. There are two common ways to do it. The old way was the have some type of device to either manually reconnect and automatically reconnect jumpers to match the machine to the line voltage used. The newer system uses a boost or PFC system. A switching transistor uses an inductor to charge a capacitor bank up to a set voltage. and the inverter runs off the voltage.
    I am going to guess you have a relay that pulls in on 115 volts and stay off at 230 volts. And it is stuck in the 115 volt position. This then caused the voltage to the capacitor to be double what is can handle and it exploded. Two caps in parallel on 115 and the two caps in series when on 230 volts. So look for the second cap the same size as the one that blew an check it. Both should be replaced and find the relay that reconnects them.

  6. Likes MinnesotaDave, SavedInChrist liked this post
  7. #6
    Join Date
    Oct 2018
    Posts
    17
    Post Thanks / Like

    Re: Blew up CT312 welder today! Help with wiring

    hi thanks yes ordered 2 replacements already - interesting cos i saw 4 caps there.. im pretty sure its a wiring thing - they are rated for dual voltage but not in the sense that one can easily switch -

    I think they come hard wired for either-

    I would love to figure out how to add a switch.. my elec exp is limited on the finer circuitry- no prob soldering in caps / etc-

    Would uploading some pics be of any help?

  8. #7
    Join Date
    Oct 2018
    Posts
    17
    Post Thanks / Like

    Re: Blew up CT312 welder today! Help with wiring

    Quote Originally Posted by ccawgc View Post
    I am going to guess you have a relay that pulls in on 115 volts and stay off at 230 volts. And it is stuck in the 115 volt position. This then caused the voltage to the capacitor to be double what is can handle and it exploded. Two caps in parallel on 115 and the two caps in series when on 230 volts. So look for the second cap the same size as the one that blew an check it. Both should be replaced and find the relay that reconnects them.
    and yes this in an inverter style welder (newer)0 - bought it 3-1/2 years ago.. small & compact and does pretty well for small home jobs.. but id love to get the 230v working too..

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Page generated in 1,619,122,405.03137 seconds with 14 queries