Hi-Freq box problem

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I have a Hi-Freq tig box attached to a miller as its power source. The hi freq runs off a 115v lug, but my manual said i could wire it the fan motor inside the power source to eliminate the need for the 115v plug in..So thats what i did and it worked for about 2min then lots of smoke came out and pop! i opened up the box and found a transformer that was melted..I figure that since the power source was 220v so was the fan motor and when i hooked it up it overheated the transformer and melted it.but here is where the problems start, this transformer is an obsolete part and i cant get the exact replacement..I did some reading and i found out that its a 115v to 24v transformer, so ive tracked down a 220v to 24v thinking that by using this i could utilize the fan motor in the power source and everything would work fine..Nope! i wired up a replacement transformer using the wiring diagram i had but i cant seem to get it to work now, that old transfomer looks nothing like these new ones..anyone have any ideas what i can do to get this thing going..ps sorry for the long post.
Reply:The only transformer in my HF unit is a 115 / 3500v or so.What brand is your HF box ?
Reply:It's the Lincoln 500amp box model #5569 the transformer is just a small one, the diagram calls it transformer(timer). I'm going to try a different one tonight. Just gonna go back to the115v input and forget about trying to get it to run off the power source.
Reply:I hate to say it, I think you have a bigger problem. The original transformer is 115v in and 24v out. The turns ratio is 115/24 = 4.7916 volts per volt. You connected it to a 220 volts source, 220/4.7916 =  45.6 volts. Not only did you fry the original transformer, you also fried the electronics with twice the input voltage. SORRY. Repairable? Don’t know.
Reply:I thought that might be the case, but I checked all the resistors and they all checked out fine, so I'm hoping I got lucky, I probably didn't but I guess I'll find out tonight when I test it with a different transformer.
Reply:Originally Posted by mofugraI thought that might be the case, but I checked all the resistors and they all checked out fine, so I'm hoping I got lucky, I probably didn't but I guess I'll find out tonight when I test it with a different transformer.
Reply:WOOHOO! i got lucky, popped in a new transformer and voila! Note to self, dont mess with electrical stuff in the future!
Reply:Originally Posted by mofugraWOOHOO! i got lucky, popped in a new transformer and voila! Note to self, dont mess with electrical stuff in the future!
Reply:Originally Posted by mofugraWOOHOO! i got lucky, popped in a new transformer and voila! Note to self, dont mess with electrical stuff in the future!
Reply:Originally Posted by transitLucky!!!!  Don’t understand why the 220-24 volt transformer didn’t work.
Reply:Wait a minute.....Let me get this straight.....You opened up the case of the HF box? the blown transformer was in the HF box? Or the blown transformer was in the Miller?And did you hook up your HF box to the OUTput of the transformer? Or to the INput of the transformer? So you were either seeing 24v to your HF box or you were seeing 220v to the HF box? Either way, would be wrong if you actually needed 115v.  Or am I missing something in the story. I can't figure out why you would do that. You definitely got lucky. But instead of relying on luck, next time why don't you get out your DMM and check voltages BEFORE you hook anything up? That would make sense.Lincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:I'm puzzled too. the 220-24 v transformer should have worked hands down.
Reply:mofugra,Where you went wrong was wiring the HF box 115v input to the welder 220v input if I understand your post correctly.  If you read the manual again you'll see the reader is instructed to connect the HF 115v input to the welder 115v fan power supply from the welder stepdown transformer secondary as an option to using a seperate 115v power source.  My intent is not to be rude but the manual also indicates a qualifird electrician should be consulted if there is any uncertainty as to how to do it.You definately dodged a bullet on this one.Just curious - what's the Miller machine and its SN?Last edited by duaneb55; 02-12-2010 at 10:48 PM.MM200 w/Spoolmatic 1Syncrowave 180SDBobcat 225G Plus - LP/NGMUTT Suitcase WirefeederWC-1S/Spoolmatic 1HF-251D-1PakMaster 100XL '68 Red Face Code #6633 projectStar Jet 21-110Save Second Base!
Reply:Duane, So where in the heck is that 24v going to? Why is there a need for 24v in there? Is it for a control circuit somewhere? Or is it to power an led display? help me out here.Thank you, come again,JokerLincoln Power Mig 210MP MIGLincoln Power Mig 350MP - MIG and Push-PullLincoln TIG 300-300Lincoln Hobby-Weld 110v  Thanks JLAMESCK TIG TORCH, gas diffuser, pyrex cupThermal Dynamics Cutmaster 101My brain
Reply:Originally Posted by Joker11Duane, So where in the heck is that 24v going to? Why is there a need for 24v in there? Is it for a control circuit somewhere? Or is it to power an led display? help me out here.Thank you, come again,Joker
Reply:Originally Posted by duaneb55mofugra,Where you went wrong was wiring the HF box 115v input to the welder 220v input if I understand your post correctly.  If you read the manual again you'll see the reader is instructed to connect the HF 115v input to the welder 115v fan power supply from the welder stepdown transformer secondary as an option to using a seperate 115v power source.  My intent is not to be rude but the manual also indicates a qualifird electrician should be consulted if there is any uncertainty as to how to do it.You definately dodged a bullet on this one.Just curious - what's the Miller machine and its SN?