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  #261  
Old 04-01-2009, 02:40 AM
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GWIZ GWIZ is offline
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Quote:
We've had an exceptional spring here in southern Ontario. So I took yesterday off and drove back up north with a friend, to see the river at the back of his 100 acres.


SR3 AC leads go to the pair of transformers at the front left(driver's side), and SR2 AC leads go to the right side pair of transformers.

Lead #86 can be unbolted easily, so I will go ahead and tape it up. Should the small capacitors remain attached to #86 lead?
__________
As the weather gets better more immediate projects keep popping up.


Ok so that's like my picture #1 in post # 257
You got a typo, its #68 and not 86.

You can leave the capacitor connected to the heat sink.
Tape up 68 (you did that). also disconnect the two wires that connect T2 to the negative side of the welding lug (Tape the two up).
That should now have T2's secondary output disconnected from the welders T1 bank.

Make sure the two from T1 stay connected to the Negative welding lug.


With pm3 and pm4 removed and wires taped up, that should now have the primary power that feeds the primary winding of T2 isolated and not powered.

____________________

This test, I don't know what will happen, that's why we are doing it.
The main board may shut every thing down or T1 bank may start up if we are lucky.


Same switch settings that we have been using.

Switch,------CC/CV to = CV
Knob,------- Amperage\Voltage set to = lowest voltage.
Knob,-------Arc control set to = 0
Switch,-----A / V to = Panel
Switch, ----OUTPUT (CONTACTOR) to = REMOTE
=


Connect the amp meter to the ac power cord as before.
Connect your volt meter across the DC output side of SR2 that's on the bread board.

No, 20 ohm Load resistor.

Power it ON.
Switch contactor to ON.

Check for the DC voltage at SR2 that's on the bread board.
Check for any voltage output at the welding lugs.
Do you hear any of that high frequency squeal or that ticking ?

=
If you don't get any voltage readings above 5 volts from Both SR2 and the welding lugs.
repeat the test with the 20 ohm resistor load on the welding lugs.
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  #262  
Old 04-02-2009, 08:34 PM
VW cat VW cat is offline
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GWIZ,
I unbolted the 2 leads from T2, the pair of transformers on the left(drivers) side of the machine. I separately taped them well and made sure both leads from T1 were bolted back to the negative welder lug lead. I reconnected the 2 tiny capacitors back to the heat sink where #68 was bolted. I rechecked #68 to see that it was well taped. I also rechecked PM3 & 4 leads to make sure they were well taped and clear. I made sure the red and white leads to PM3 & 4 were taped and clear also. Getting more cautious. Made sure the big 20 ohm resistor was disconnected. Machine powered up okay.

Switching the contactor switch to 'on' there was immediately a bang and the fans went off. The main panel breaker tripped also.The IGBT PM2 has a funny look to it. I was going to poke it with a stick, but it looked dead so I'm leaving it until morning. Phil
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  #263  
Old 04-08-2009, 02:58 AM
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GWIZ GWIZ is offline
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If we blew another IGBT, its time too cut your losses.
I would reassemble the welder back too its original wiring, keep whatever good IGBT's, maybe for your next project.
reinstall the bad ones.

If you were on the US side of the boarder, you probably could get $150 to $200 on e-Bay. that would give you a profit.
On the US side before the economy went south there were quite a few welder repair outfits buying up alot of broken welders, they were paying top dollar on e-Bay.
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  #264  
Old 04-08-2009, 04:59 AM
VW cat VW cat is offline
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Thank you for all your help GWIZ. You deserve a medal for your perseverance. Phil
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  #265  
Old 04-14-2009, 11:59 AM
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I have been away for two weeks sorry it ended like this.
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  #266  
Old 04-14-2009, 08:27 PM
VW cat VW cat is offline
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I've enjoyed the experience Terry and as my son said where else would one get to learn all that we have covered without paying a lot for it. GWIZ summed it up best, it's the journey, not the end result. I've got my son stripping the machine apart. I told him to watch for anything suspicious, like a wire in the wrong place or shorted. Need any parts? Phil
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  #267  
Old 04-21-2009, 01:36 PM
Whattman Whattman is offline
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VW,
Sorry that it didn't work out. I haven't been following this thread for a while. This welder looked like it was going to be much harder than your
other one so I thought I would just stay out of it this time. Besides, "Too many cooks,....".
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  #268  
Old 04-21-2009, 05:58 PM
VW cat VW cat is offline
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Whattman, thanks for the interest. I would do it all over again just to get a chance to work with GWIZ again.

I knew our chances were not good from the start when a welder repair shop did not fix it, with all their special equipment, and the machine right there in front of them. And who knows if they put it back together right, before I got it.

I know where there's a Linde 250A mig welder. It looks good on the outside. Phil
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