lincoln Hi-Freq 500 amp box with bad relay?

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Hello,  Have a older Lincoln Hi-Freq 500amp box with a burnt relay in it.  The manufactures code is: 5835.  By an odd chance they still have a few of the relays, but list them at $250.  The tech and salesman both thought it outrageous.  Even if that were all of the problem for sure I'm not ready to give them $250 for what is really just a small 120v relay  about the size of your thumb.  A bit different looking.  Possibly relay # 2 from their on line drawing.  Anybody have a clue if a generic relay can work here?  I have the schematic.  The relay is bolted through the side wall with a small screw, on the upper right side when the rear panel is removed.Thanks,Alan
Reply:Hey Allen,If you can get a generous tech guy at Lincoln to get you the switching and coil specs, you might find a suitable replacement.  It looks like, AND I AM BY NO MEANS AN EXPERT, all that Relay 2 does is to use 1 pole to switch on the Hi-Freq for start only (the other pole is always closed)  If you don't mind Hi freq all of the time, jump the leads on the the SPDT Spark Switch to operate "On" or "Off", and lose the "Start Only" function.  The problem I see is that most relays are for "conventional" currents and voltages, and Relay 2 looks like it has to handle and switch high-voltage, high-frequency, and low current.  Again, I am no expert, so consult your Lincoln tech guy to get the straight poop on by-passing the relay as a work-around, until a replacement can be found!!!!!Good Luck,cricmanp.s., is that the one on ebay from about 4 weeks ago?
Reply:Hey Allen,If you can get a generous tech guy at Lincoln to get you the switching and coil specs, you might find a suitable replacement.  It looks like, AND I AM BY NO MEANS AN EXPERT, all that Relay 2 does is to use 1 pole to switch on the Hi-Freq for start only (the other pole is always closed)  If you don't mind Hi freq all of the time, jump the leads on the the SPDT Spark Switch to operate "On" or "Off", and lose the "Start Only" function.  The problem I see is that most relays are for "conventional" currents and voltages, and Relay 2 looks like it has to handle and switch high-voltage, high-frequency, and low current.  Again, I am no expert, so consult your Lincoln tech guy to get the straight poop on by-passing the relay as a work-around, until a replacement can be found!!!!!Good Luck,cricmanp.s., is that the one on ebay from about 4 weeks ago?
Reply:Hi Cricman,  I'll do just that, contact a tech guy at lincoln.  Had thought about bypassing it  but wasn't too sure of my interpretation of the schematic, and the hi-freq spooked me.   But I will want the start only option.  Bought this thing of an employers auction years ago.  It hasn't seen much use, especially from me, it's been ten years since I last used it.  Will need it soon though.Thanks,Alan
Reply:If thats the case, maybe a momentary push button on the torch to enable the arc, then just let off after the flame is initiated.  Does the relay have any numbers on it?Various GrindersVictor Journeyman torch200cf Acet. 250cf oxygenLincoln 175 plus/alpha2 gunLincoln v205t tigLincoln 350mpEsab 650 plasmaWhen you can get up in the morning, Its a good day.Live each day like its your last.
Reply:HI Doolittle and Cricman,  Found a link in the forum to lincoln tech pages.  Found the side view drawing  and it appears that it is D.C. relay #1, not #2.  Item number 18 on page 10 of:http://content.lincolnelectric.com//.../im/IM238B.pdfAnother look at the schematic and I am more unsure of what it is doing.  It is an unconventional looking relay, don't recall any numbers off hand.Thanks,Alan
Reply:On page 6 of that manual you posted, it mentions something about dc relay #1 being involved in a high frequency turn-off delay circuit.You probably already saw that, just posted this in case you missed it.- John
Reply:No, i skipped over that.  It will be the agenda when I talk to some one at Lincoln.Thanks,Alan
Reply:Alan,  The Relay #1 is only controlled by the control switch, it's not connected to the timer by any means. If you could read some markings on it or even better take a photo we could come up with a sutable replacment. Just looking at the schematic there's nothing special about it, it just looks like a normal 2 pole relay operating at on not much current.(only a few amps max it appears).
Reply:You are right, it's not as unusual looking as I remember.  On the metal stamping it says: 10 amps, 1/4hp, 115v AC.  There is a close up of the relay and wider views of the interior in the lincoln tig box album located here:http://new.photos.yahoo.com/castiwaysoff/albumsThanks,Alan
Reply:A replacment sould be easy to find. Before that happens though, have you powered the unit on and pressed the control switch while watching the relay? That thing is bigger than I imagined from the schematic, so I find it hard to believe that the coil winding is bad. Acording to the schematic the welding machine need not be connected for this relay to open and close, the only thing needed it ac power, unit turned on, and the control switch to be pressed. When the control switch is pressed relay #1 should close until you release the control switch. If this works I would try using some 330 sandpaper and sanding the contactors on it to clean them up. And try the unit again. If the relay does not close let us know and I'll dig around to see if there is somewhere you can get a cheap replacment.
Reply:I'm with OCD,It doesn't  seem like the coil is bad (though there is always that chance.)  It also doesn't sound like the specs are anything out of the ordinary.  It looks like relay 1 simply allows the use of low voltage at the "arc start switch" to isolate the user from the line voltage that energizes the gas and water solenoids, and the high-frequency circuit.  That should be a very easy relay to find, since the manual itself says that the box only draws about 3 amps.  The other thing that you might check with a voltmeter is the output of the small transformer that is near the bottom of the schematic (there is a small bridge rectifier and a filter cap on it- On the parts list and drawing it is #15 on page 10 and in your pic, it is next to the relay in question.)  That will give you a good idea of the "coil" voltage of the relay, if that transformer is actually performing correctly.Again, I am no trained electrical engineer (highly trained baboon is a more accurate assessment), so I would definitely talk to the Lincoln dude if you have any doubts.Keep us posted,cricman
Reply:Also since that is an open relay with the contacts exposed, after watching and verifying it truly doesn't work (and verifying that voltage appears across the coil, 'trying' to energize the relay), you could manually push the contacts together and see if the rest of the beast works as you expect. Kinda simulate what will happen when you replace it with a working relay.Of course you'd do this with something non-conductive so you don't get the zap-zowie treatment yourself.On second thought, pretend I didn't even suggest this - John
Reply:Here's a 30-amp relay, check out the price, 15 bucks.http://www.factorymation.net/s.nl/it.A/id.725/.fI'm not saying it will work for your app, since we don't know the coil voltage, but it gives hope that it won't break the bank to replace it. - John
Reply:Thanks for all the suggestions!   Found out there is no juice to the relay, and for the smoke that filled the shop it looked surprisingly clean.  Crickman mentioned that transformer #15 (timer) from page 10 and sure enough, that was burnt out on the bottom end and spilled it's gummy deposits over the rectifier below.  It was getting late so I didn't get a chance to see all that it was connected to.  This is probably something I should look at replacing before seeing what else might be wrong, it might be the only problem, HOPEFULLY!The number on the transformer frame is S12791-A, this is listed in the Lincoln parts pdf as part #15,  S12791-1A on  page 9.http://content.lincolnelectric.com//.../parts/P67.pdfSince it's still listed as in stock, I will check again on prices and see if this little guy can be had for a reasonable price.  There are no specs listed for it.Thanks much, I'll tell you what they say tomorrow.Alan
Reply:The part is no longer stocked, but the tech guy at lincoln sent out a full spec sheet.  Just a regular 24v transformer.  Hope this is it.Thanks for all the help,Alan
Reply:Good news, and thanks for the update. I was looking at your photo again last night and I noticed that the transformer just behind the relay and below the yellow capacitor was burnt looking on the bottom side, I decided that it could be normal for the age and type of equipment so I did not mention anything.  If thats onlyn a 24 volt transformer you can get one almost anywhere, just be sure to get one at min. that meets the current rating of the old transformers secondary output.
Reply:Cool beans Alan,I recon a 30-40VA transformer ought to be fine.  I say this because the coil voltage is 24 volts, and the transformer is not very "heavy duty" looking, 30-40va (about 1-1/2 amps continuous) should be more than adequate for the solenoid coil.  Be careful when you get near the filter capacitor that is part of that power supply, it might still hold some juice.  A 24v, 20-40VA transformer should run you about $6-$10 plus shipping.  They are very common in the heating and air conditioning trade.  Good luck and, again, keep us posted.cricman
Reply:Yes I am pretty leery putting my fingers in there.  Being in the HVAC trade I have saved a box of them, just need to find that box...Thanks again,Alan