ESAB Smashweld 180

[Mclinden]

New update.
I remembered wrong. The voltage is only from 14V to 30V, and a little bit higher on the DC side, which make sense from a 3-phase transformer.
Or does it doubble and then you have to times the reult by 1,73? I have forgotten how the rectifying of 3-phase work.
If doubbled and times 1,73 it make more sense with the voltage measured.

When I touch with the welding wire against the ground clamp, the voltage drop to zero, but the feeder motor is still running, and it comes from the same source.
Maybe some diodes are working, and enough to feed the motor, and when I try welding there is another phase beeng tapped, caused by some broken diodes?

Guess I have to disconnect and check the K2 diodes. This is only making more questions than answers, as I don't know what the voltage from the AC side of the K1 transformer is suppose to be.

Sorry for thinking loadly here

[Mclinden]

Hi QV.
Thank you for your always enlightening input
Then I think that some of the K2 diodes are broken and causing this weird behaviour.
It make sence if some and not all diodes are burned.
You could easily get a voltage when not loaded, but when shorted, there is no amps behind it to start an arch.
Almost like a static voltage.

I have started to take apart the diode bridge, to check every diode, and I guess I will find the problem here.
I will let you know, when I have checked them

[Mclinden]

Last update for tonight. Work tomorrow

I have checked all the K2 diodes and found them OK. No leak and 234K ohm measured the other way on all the diodes.
The high resistance is probably caused by the low voltage from the instument.

It looks like there is a cable missing between minus and chassis (ground cable clamp).
The cable to the welding head is connected to the inner plate, which is plus, but from the other plate, which is minus, there are only 3 small cables connected.
That is the 036, 037 going to M14 emitter and the 097, going to the K8 contactor.

Here is a picture under, showing how it looks like, with the plus cable connected to one plate(+), but nothing for the minus.
Does anybody have a picture of how it looks in their machine?
Do you have a thick cable going from the other plate to ground/shassis?
There must be a proper connection between the minus plate and the grounding clamp cable, which is connected to the chassis.

PS. The wiring for the thermostate is not connected yet on the picture

[Turbodiesel]

The ground clamp (or the 'hot' lead) should not be directly connected to the machine frame (chassie). That leads (sooner or later) to burnt ground wires, in both the machines mains cable, and various places in your shops electrical, when the current takes other paths.

The ground connector from the protection and interference filter (K27 & K56), should be the only wire (chassie)grounded in the secondary circuit.

Are the cable between the diode negative plate, and the ground clamp connector missing, or (incorrectly) connected to the chassie?

[Michael Meier]

[Mclinden]

Hi Guys.
Thank you very much for your feed back here.
I understand how you mean now.
I thought the minus (clamp) cable was going from the minus plate via the chassis and out to the ground clamp.
This because of the cable from the ground clamp now beeng connected to the chassis, and I thought there were missing a piece running from there to the minus plate.

The problem seems to be that they have just connected this cable at the wrong place, because they thought ground was ground.
This cable is supposed to be disconnected from the chassis and connected directly to the minus plate instead.

I will let you know the result when I have connected everything correct.

[Mclinden]

Hi Guys.
New update on the project

When I came today to connect the minus cable to the correct connection point (the rectifier aluminium plate) the macine was compleetely dead.
Nothing was working on the card. The relays didn't activate and it looked like it did when I fisrt started.
I started to check the voltage from the transformer, and it was OK to the card.
Next I checked after the rectifier, and found 2V.
Conclusion. I need to change the rectifier.

The rectifier is 1,2A and should not burn, unkless something was pulling too much current, for a reason.
Feeding the two relays and the electronics should not exceed 1,2A.
I guess I will find out, when I replace this with a bridge rectifier capable of up to 5A.

However, I tried to activate the contactor manually to check if there was suficient welding power, when connecting the minus cable correct, directly to the rectifier plate, and YES, that was the problem.
They had connected the cable to the chassis instead of connected it to the rectifier minus plate.

I will try to replace the bridge recifier to a 5A that I found among all the electronic components I have collected over time, and update you on the result, when this is done, later tonight.

[ÅkeB]

Thanks for your great sharing of info. I have a broken Smashweld 180 as well and I supect that it is the Transformer that is broken as ther is no power on secondary side. I follow you repair with great intrest. I have a spec of the transformer that I whant to share and maby be of intrest. If you have more info of your Winding setup I would be intrested of some pictures.

[Mclinden]

Hi ÅkeB.
Thank you very much for the transformer information.
I have never seen any documentation for the transformer before, but this is great news.

There is no doubt about your transformer has burned the primary windings, if there isn't any voltage to be found on the secondary side.
You can doubble check this by using an Ohm-meter to see if there is any contunity between brown/red and orange/red.
If you need any more information about how to rewind it, you are free to ask anytime for information and help.
You can also E-mail me directly at jasimons@online.no If you want.

It seems like my voltage is a little bit too high, as I measure 20 and 49V.
I will need to add some more windings to the primary side to get the voltage down to the correct voltage.

The set up for 230V / 400V will then be:

Primary windings: 6,2286 windings/Volt
Brown -Red. 0 → 230V. → 1 430 Wingdings.
Orange – red. 160V. → 996 windings. From 230V to 400V
Brown - Orange. 0 → 400V. → 2 426 windings total.

This may be the reason why the rectifier bridge on the PCB burned out.
I will upload pictures from the winding process later (using a lathe and an optical counter).

It is not very complicated to rewind the transformer.
The only thing is that you will have to damage the two first slats in the transformer core, to get them out.
There is som enamel/clear lacquer on the transformer, causing them to stick together, but after the two first are out, it is quite easy.
It doesn't matter with the two missing slats, as they will only cause the lack of power (VA) to be a fraction of the total.
It is also easier to assemble the core, as I could not manage to get more slats back in anyway.
I will update here when I have more information.
When I have added the correct windings to the primary, I will upload pictures of the winding process and the transformer for you.

[torbjorn_forsman]

Note that the voltages given in the transformer drawing are stated at rated load of both secondary windings. At lighter load, the voltages will be higher.

That type of transformer, with a split bobbin, uses to have a high leakage inductance and so also a high voltage drop, it is not uncommon that no load secondary voltages are 20-30 % higher than rated load voltages.

[Mclinden]

Hi Torbjorn.
You are right oabout that.
I will check, and adjust the voltage with the rated load, stated in the transformer specification.
That way it will be exactly right.

[Mclinden]

Hi again.

The specs are saying that the voltage is with constant load, meaning I have to find something I can use as a load.
That will have to be tomorrow

The continuously load at 42V secondary coil is 23VA.
Using an estimated power factor of 0,9 for VA → 20,7W resistive load.
It is impossible to calculate the power factor without knowing the Gauss in the core, and this is why I use an estimated factor, which is not too far away from the real factor.
This should bring us close enough to get a voltage close enough.
The resistive load has to be 21 Ohm and 84W for testing.

The most important is the voltage for the PCB, which is pulling a very low current.
It is only supplying the electronics and two small relays.

The PCB will burn components, if the voltage is too high, but the other (42V) side is not very fragile to the voltage.
I will let you know tomorrow, when I have made a load of 21 Ohm and tested the voltage at load.
This will tell us the exact number of windings at the primary side.

[Mclinden]

Hi again. New update for the auxillary transformer

There is some wrong calculations in the previous update. I think I was too tired last night

Today I recalculated and found the following:
For the 23VA. Continuously load at 42V. Using an estimated Power factor of 0,9 → 20,7W resistive load.
I = 0,548A → resistive load = 76,64 / 0,9 = 85,15 Ohm continus Load.

I found some elements from an old micro oven, and an old resistor form a car fan control.
When connecting them in series, I got 85 Ohm, which is more than close enough to 85,15 Ohm, for testing the voltage under continius load.

Here are the results I calculated to be the number of windings and the voltages mesured after rewinding the transformer again.

For 220V and 380V setup (original)
Primary windings: 5,773 windings/Volt
Brown -Red. 0 → 220V. → 1 270 Wingdings.
Orange – red. 160V. → 924 windings. From 220V to 380V.
Brown - Orange. 0 → 380V. → 2 194 windings total.
Open circuit voltages measured:
17,46V and 45V. (Secondary side voltages).
With Load.42V and 16,89V

For 230V and 400V setup
Primary windings: 5,773 windings/Volt.
Brown -Red. 0 → 230V. → 1 327 windings.
Orange – red. 170V. → 981 windings. From 230V to 400V.
Brown - Orange. 0 → 400V. → 2 308 windings total.
Open circuit voltages measured:
45V and 17,46V. (Secondary side voltages).
With Load.42V and 16,89V

I think this is as close to perfect as possible to obtain!

PS: I will be back with more updates, when this is installed and the welder is working again.

For ÅkeB.
Here is a picture of how I did the winding set-up with a small leith. This is what you were asking for?
Mark! When taking apart the transformer, there is wan plastic ledge covering a little bit of the primary windings.
To be able to rewind the transformer primary, this ledge has to be removed.
I just used a knife and carefully cut it off, without damaging the wall separating primary and sekondary windings.

[Mclinden]

Hi again. New update for the auxillary transformer

There is some wrong calculations in the previous update. I think I was too tired last night

Today I recalculated and found the following:
For the 23VA. Continuously load at 42V. Using an estimated Power factor of 0,9 → 20,7W resistive load.
I = 0,548A → resistive load = 76,64 / 0,9 = 85,15 Ohm continus Load.

I found some elements from an old micro oven, and an old resistor form a car fan control.
When connecting them in series, I got 85 Ohm, which is more than close enough to 85,15 Ohm, for testing the voltage under continius load.

Here are the results I calculated to be the number of windings and the voltages mesured after rewinding the transformer again.

For 220V and 380V setup (original)
Primary windings: 5,773 windings/Volt
Brown -Red. 0 → 220V. → 1 270 Wingdings.
Orange – red. 160V. → 924 windings. From 220V to 380V.
Brown - Orange. 0 → 380V. → 2 194 windings total.
Open circuit voltages measured:
17,46V and 45V. (Secondary side voltages).
With Load.42V and 16,89V

For 230V and 400V setup
Primary windings: 5,773 windings/Volt.
Brown -Red. 0 → 230V. → 1 327 windings.
Orange – red. 170V. → 981 windings. From 230V to 400V.
Brown - Orange. 0 → 400V. → 2 308 windings total.
Open circuit voltages measured:
45V and 17,46V. (Secondary side voltages).
With Load.42V and 16,89V

I think this is as close to perfect as possible to obtain!

PS: I will be back with more updates, when this is installed and the welder is working again.

For ÅkeB.
Here is a picture of how I did the winding set-up with a small leith. This is what you were asking for?
Mark! When taking apart the transformer, there is wan plastic ledge covering a little bit of the primary windings.
To be able to rewind the transformer primary, this ledge has to be removed.
I just used a knife and carefully cut it off, without damaging the wall separating primary and sekondary windings.

[Mclinden]

Hi again.
New update on the transformer.
I took the time to make connectors for the transformer, which make it easier to take things apart, if needed one day.
Now it is just to unplug the transformer and take it out.
I also made a new plate to put the connection strip to, as the original was in a way where it is no room for a screw driver.
Now it is vertically and the screw driver is inserted in from the side.

I found that (for a strange reason) the 400V produced a higher voltage than the 230V, when testing it in the machine.
It will be recommended to add about another 100 windings from the 230V to the 400V terminal.
Using 1 090 windings from 230 to 400V should do the trick and give you 17V for the PCB.

I tried now to hook up everything again, with a ned bridge rectifier and everything worked now.
The only thing now, is to check the connection for the welding wire tube.
When moving it close to the machine (where it is fastened), it looses contact with the trigger button on the handle.
I have never had this part off, so I guess I will have to figure out how it is assembeled.