HELP.... No trigger response from my MIG Welder after Making a HUGE mistake.

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I have a Century 125GS MIG welder.  Some time ago, I modified it by installing a Contactor so that the gun trigger would control power to the feeding wire (welder trigger originally only controlled power for wire feed and wire was hot when machine was turned on).Today I made a horrible mistake.  I have a 120/240 plasma cutter and without thinking, I plugged the Century welder into it's cable, which was operating on 240V..  Arc struck once, then POOF.... no wire feed or power.

The cooling fan still runs and I can get wire to feed manually by pushing the Contactor's button, but it does not activate power transfer to the feeding wire. I see no burnt wires or components...          - How do I diagnose what component got fried?        -



Reply:I would check the diodes first. There aren't any real electronics in that thing. So if its not the diodes, you likely fried the transformer.

Miller Multimatic 255
Reply:But Wait,,,, you have a 120v receptacle with 240v in it? How does That happen?
Reply:

Originally Posted by BaTu

But Wait,,,, you have a 120v receptacle with 240v in it? How does That happen?
Reply:Do you have continuity across the "thermal protector"  on the white wire. ie. the white wire on the fan to the white wire on the transformer ? The fan is before the thermal protector, so the fan should still run even with protector tripped. It could also have taken out your new contactor , how is that wired ? to the trigger also ? It lists all the OCV's so it should be easy to follow the voltage to its termination, and that likely will be the faulty component.Good LuckAirco 250 ac/dc Heliwelder Square waveMiller Synchrowave 180 sdMiller Econo Twin HFLincoln 210 MPDayton 225 ac/dcVictor torchesSnap-On YA-212Lotos Cut60D
Reply:Taker a single strand of 12ga insulated wire and lash that adapter semi-permanently to the plasma cutter's cable.HF MIG-180 with all the mods.Grizzly H8153 Stick/Tig Pulse 130/160.Wards PowrKraft AC-230. Stick & carbon arc.
Reply:Is the wiring diagram on the inside of the lower side cover, (below the access to the wire spool and wire feed roller assembly?I spent a bunch of time looking for a wiing diagram for my red Century, then turned red, myself, when I pulled the lower side cover and found the damn wiring diagram!  LOLTheoretically, you should have pooped/popped the circuit protector wired into the big-azz coil sitting under the rectifier.  That's what it's for, over heat, overload protection.  Not really understanding if you ran 240V through it, or what, since I don't understand exactly what you did, I can't say for certain. Did anything smoke?Look at the wiring diagram, (if it's not there, let me know, I may have one, or be able tog et you to one.)  Louie1961 may have posted the correct one for you, but you didn't give the model number.If you have the correct wiring diagram, pull all the sheet metal off the welder, and look at the wiring and the diagram until you see and understand their connection.  Not the connections, the connection between the diagram and the actual wires.  Cut all the zip ties off.Once you understand what correlates between the real world and diagram world.  Start labeling everything.  I've been doing this since Christ was only a corporal, and I STILL use white masking tape for the white connections, and black tape for the black connections. Sometimes, a wire will be black, but make a 'white' connection.  Or vice versa. Or a yellow connects to a white or black. THAT is where mistake get made.  Use brown masking tape to make labels when wires connect to components.Once you understand real world vs diagram world, have everything labeled, then,and only then disconnect anything.  Make sure you can take every connector off, and put it all back together.  Take before and after pics, (I'm waaaay older than the cell phone era, and never think of pics. My mid still defaults to processing film!)Once you can take it apart and put it back together, then take everything apart. ALL connections.  DO I need to tell you to unplug the effing thing, too? I doubt it... after what you did, you're likely scared to plug in your toaster, now... that will go away in a couple days.When everything is apart, you need a piece of paper, and a volt ohm meter, and you need to check every piece of wire, every connection on every component for a continuity beep, first, then for ohmage.You WILL find the dead stuff before you run out of things to test. When you test the red, orange, yellow, green and white wires disappearing into the transformer, you should be checking each of the colors against the white wire, based on louie's diagram. Each should have a different ohmage.The two vertical lines between the half round lines where the colored wires are on the left, and the Heat 1-4, reactor coil, wire feed control, etc are, means there is no direct connection between the sides divided by the two lines.  It is a magnetic connection.  (Notice the Reactor Coil only has one set of double lines? That's because the reactor coil is only half of a transformer.  It needs to have continuity between it's two wire ends, and NOT be ground out to the big chunk of rusty metal it's in.)If you didn't let any magic smoke out, then nothing should be ground out in the coils.  Most likely, if you sent 240VAC through things, you cooked the little wires in the wire feed, CO2 solenoid, and possibly in the control switch(es), if they have little coils of wire.If you get to through my nickel lecture on how to troubleshoot and haven't found dead stuff, let me know.  IF you have, and know what dead, or want to bench test it to make certain it's dead, (always a good idea before buying replacement parts), let me know.   Louie may be right on popping the diodes, they won't smoke, but the transformer would smoke like mad.The contacts could be cooked in the gun, or anywhere else you see switch symbols, (those are two dots with angled line NOT connecting the dots.) They will cook just like points in a car... oh yeah, cars don't have points, any more... LOL  BUt, you'll see, from the diagram, below, the gun does have point contacts.  Too much current/voltage WILL cook them.  Connect your continuity beeper to each of the connections to the MIG gun. When you push the button, it should beep.  Test the voltage ('heat') selection switch the same way, between the black terminal and each colored terminal connection.My advice is don't check this, then check that, based on what anyone tells you. Follow a set method and protocol for disassembly, re-assembly, then testing.  When you get the thing apart, and don't get a replacement part for several weeks/months, you don't want to be lost when you put it back together.  You want it to be like getting together with an old friend.GeoD
Reply:What plasma cutter do you have that uses a 120 volt plug for 240 volts? Something doesn't seem right and actually seems like it could create a dangerous situation. Lots of inverter machines automatically adjust to the voltage but sure don't do it with a 120 volt plug. Be glad all you did was damage or burn out your Mig welder.
Reply:

Originally Posted by Welder Dave

What plasma cutter do you have that uses a 120 volt plug for 240 volts? Something doesn't seem right and actually seems like it could create a dangerous situation. Lots of inverter machines automatically adjust to the voltage but sure don't do it with a 120 volt plug. Be glad all you did was damage or burn out your Mig welder.
Reply:

You can see one in this photoYES Welder Plasma cutter 124/240v machine

Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:My   cheap  hitbox   tig  came  with a dual voltage  adapter  like  that.  Its  a 200 amp  supposed to be 60%  at  200 amps.   I have never even tried it yet