the snooper
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you shouldn't be getting a reading between the earth clamp and tip of the torch unless you pull the trigger
- Thread starter A1EK
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Well I did on mine, I would think it is either some resistance from the relay coil or part of the control circuit.
In my pictures there are two small wires going to the control board/motor circuit to the output side of the rectifier. Even if these are a high resistance when looking with a digital volt meter the load it puts on the output is next to nothing to it seems to be measuring the small transformer rectified output. But soon changes when the trigger is pressed.
On a personal note if the welder is causing to much hassle and you want to get on with welding, then go and buy another.
Adrian
In my pictures there are two small wires going to the control board/motor circuit to the output side of the rectifier. Even if these are a high resistance when looking with a digital volt meter the load it puts on the output is next to nothing to it seems to be measuring the small transformer rectified output. But soon changes when the trigger is pressed.
On a personal note if the welder is causing to much hassle and you want to get on with welding, then go and buy another.
Adrian
the snooper
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Check power going into transformer
You have the arrows in the wrong place on that picture the AC from the transformer is on the following.
The RED dots are where the AC output from the transformer goes into the rectifier. you can see the two wires from the transformer and go to the nut/bolts.
The Green dots are the DC or rectified output. The neg side goes through the choke and the pos goes to the gun, or at least it does on mine as it is a gas mig only.
If you are not getting any AC output, I would still suspect either the front 1/2 or max/min switches and the relay, It would not be impossible for the transformer to fail, but unlikely.
Adrian
The RED dots are where the AC output from the transformer goes into the rectifier. you can see the two wires from the transformer and go to the nut/bolts.
The Green dots are the DC or rectified output. The neg side goes through the choke and the pos goes to the gun, or at least it does on mine as it is a gas mig only.
If you are not getting any AC output, I would still suspect either the front 1/2 or max/min switches and the relay, It would not be impossible for the transformer to fail, but unlikely.
Adrian
mike 109444
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the snooper
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with the welder on and trigger pulled do you get a voltage between torch tip and earth clamp and does the voltage vary when you change power setting ?
the snooper
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if he is getting a varying voltage on different settings between tip and earth clamp with trigger pulled I would be removing the crimp between the choke and main transformer and any other after the output of the main transformer, because if voltage is there then there is something restricting current flow, which is likely a bad connection
I have been trying to look at various diagrams and pictures for the 100EN and 100E and there seems to be two rectifiers out there, some with 8 diodes some with 4. Looking at some of the circuits and including this one posted by A1EK
The MOV or blue disk is on the DC side not the AC side, if you look at the one I posted that only showed two diodes the MOV is on the AC side, so I give up. If closer
then I would satisfy my self as to how it goes, but a bit of distance.
Adrian
The MOV or blue disk is on the DC side not the AC side, if you look at the one I posted that only showed two diodes the MOV is on the AC side, so I give up. If closer
then I would satisfy my self as to how it goes, but a bit of distance.
Adrian
It is on the DC side on my machine checking the pictures! But just had a major thought, is it possible that the faulty MIG has three wires on the secondary side one being a centre tap, they have swapped and changed things around in the past in which case A1EK pictures would make sense as the diodes are effectively pairs in parallel as this diagram I originally posted.
as looking at this picture. The wire I have highlighted would be the Centre Tap
So the bridge rectifier diagram becomes
Now that makes a lot more sense looking at the pictures and the way the wires are connected up.
Also the various voltage measurements being taken are going to be different from my machine and the ops, across the AC he will have double my voltage as the circuit is different.
I will remove my previous post on the other rectifier before it causes more confusion.
Adrian
as looking at this picture. The wire I have highlighted would be the Centre Tap
So the bridge rectifier diagram becomes
Now that makes a lot more sense looking at the pictures and the way the wires are connected up.
Also the various voltage measurements being taken are going to be different from my machine and the ops, across the AC he will have double my voltage as the circuit is different.
I will remove my previous post on the other rectifier before it causes more confusion.
Adrian
the snooper
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that is looking very probableIt is on the DC side on my machine checking the pictures! But just had a major thought, is it possible that the faulty MIG has three wires on the secondary side one being a centre tap, they have swapped and changed things around in the past in which case A1EK pictures would make sense as the diodes are effectively pairs in parallel as this diagram I originally posted.
as looking at this picture. The wire I have highlighted would be the Centre Tap
View attachment 81810
So the bridge rectifier diagram becomes
View attachment 81809
Now that makes a lot more sense looking at the pictures and the way the wires are connected up.
Also the various voltage measurements being taken are going to be different from my machine and the ops, across the AC he will have double my voltage as the circuit is different.
I will remove my previous post on the other rectifier before it causes more confusion.
Adrian
Can you remove the internal wires that go to the dinze sockets clean then and reassemble checking for tightness, In fact remove the two plugs from the front of the welder and measure DC from the inside of these?
the snooper
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one of my guesses is the connection between choke and transformer, it will be a crimp and I have known crimps to fail
Firstly thanks AdrainH and Snooper for still hanging in there with me and trying to help, its very appreciated and as an engineer myself dont like things to get the better of me !
I've added another photo of the items checked, with the last things I have done is to clean all major contacts inside the rectifier and at the clamps. I have also ran a new cable from the earth clamp source at the rectifier to rule out any possible bad internal connections but with no joy.
You've both mentioned about crimps failing, are you refering to the ones a the switches?
I've added another photo of the items checked, with the last things I have done is to clean all major contacts inside the rectifier and at the clamps. I have also ran a new cable from the earth clamp source at the rectifier to rule out any possible bad internal connections but with no joy.
You've both mentioned about crimps failing, are you refering to the ones a the switches?
Not sure what my mind was thinking last night, but the possibility of a joint in this bit of sleeving perhaps?
Only thing is if cut off to check it would need something over it again.
Also on you picture you have highlighted the nearing front connector, I would assume you have done the second one also.
Looking at voltages you seem to be a couple of volts down to a comparison on my mig at the gun and earth clamp. If you do take off the sleeving as highlighted and you find a joint, it would give a point to measure between that and the output of the regulator, that would be the direct output from the reg and transformer. If you then try and weld and the voltage there stays at say18 volts, but the output across the gun and earth clip drops dramatically then it would suggest the fault is on the output side. If the voltage at that pint drops dramatically (under sleeving and output of rectifier) then it points to a transformer or regulator fault, then you can measure the AC between the centre tap and each leg from the transformer secondary to see if you have a transformer fault etc and work in a direction to the fault.
You could start from the measurement you have above try to weld and see what the volts drop to under load. I wonder if you have pulled back the rubber boots on the two dinze plugs, I think these are sometimes grub screw connections. the non earth side will go back into the wire feed side and connect to the mig gun, it is just about trying to find where the set looses its power.
Adrian
I wonder if there is a load one can use across the gun tip and earth clamp that would load the transformer to an expected value?
Only thing is if cut off to check it would need something over it again.
Also on you picture you have highlighted the nearing front connector, I would assume you have done the second one also.
Looking at voltages you seem to be a couple of volts down to a comparison on my mig at the gun and earth clamp. If you do take off the sleeving as highlighted and you find a joint, it would give a point to measure between that and the output of the regulator, that would be the direct output from the reg and transformer. If you then try and weld and the voltage there stays at say18 volts, but the output across the gun and earth clip drops dramatically then it would suggest the fault is on the output side. If the voltage at that pint drops dramatically (under sleeving and output of rectifier) then it points to a transformer or regulator fault, then you can measure the AC between the centre tap and each leg from the transformer secondary to see if you have a transformer fault etc and work in a direction to the fault.
You could start from the measurement you have above try to weld and see what the volts drop to under load. I wonder if you have pulled back the rubber boots on the two dinze plugs, I think these are sometimes grub screw connections. the non earth side will go back into the wire feed side and connect to the mig gun, it is just about trying to find where the set looses its power.
Adrian
I wonder if there is a load one can use across the gun tip and earth clamp that would load the transformer to an expected value?
Okay, with much pain and sweat I've finally worked out what the problem was and it is thanks to the great help in this forum. What I hadn't realised is when people were taking about checking the crimp I thought this was referring to the switch crimps. I hadn't realised there was one that sits between the two transformers. This was the issue just not quite good enough connection and I've now rectified this and pleased to say I've been welding all afternoon!!
Thanks again for all the help guys.
I've added a photo of the culprit connection!
Thanks again for all the help guys.
I've added a photo of the culprit connection!
the snooper
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yeah, I posted that 10 days ago
that's why I asked if the voltage changed when you altered the power switches, if it does then its working but you have resistance, glad you got there in the end 
