Gouge lashup

[Jim Davey]

Hi folks, ever needed to double the capacity of a stick set?

Couple both negative terminals to one lead, same for the positives.

Set both machines to aproximately half the amps you need, say 200-200 to get 400, I use a remote with two pots on the same shaft and a link/splitter box.

I can get 900 amps out of these two babies!

 

[eSCHEn]

Hellfire that's gonna burn some rods!

I had no idea you could do such a thing.

 

[Jim Davey]

They are off out for burning 6 and 8mm gouging carbons with an arc/air setup, mmmm sparky!

 

[rtbcomp]

Word of caution - do not try this with buzz-boxes unless you are sure the outputs are in phase and the open circuit voltages are the same.

 

[Jim Davey]

No, that wouldn't be a great idea at all!

 

[Bill Edwards]

Presumably if you wanted to do this with AC buzzboxes you could if both boxes were the same (equal share of the work and the same voltages) if you had some suitable diodes to give them both a DC output before they're coupled together?

 

[Maker]

Word of caution - do not try this with buzz-boxes unless you are sure the outputs are in phase and the open circuit voltages are the same.

Why not? I must be missing something.

EDIT: Are buzz boxes AC only, that would explain what you mean.

Will this system work with TIG welders too?

 

[Jim Davey]

Because if they are not in sync with eachother one will be putting out negative while the other puts out positive. At best this will reduce current as they will cancel eachother out but at worst it can damage the transformer.
Best not to attempt this unless you are very famiar with the kit in question.

 

[Jim Davey]

Presumably if you wanted to do this with AC buzzboxes you could if both boxes were the same (equal share of the work and the same voltages) if you had some suitable diodes to give them both a DC output before they're coupled together?

Yes, coupling after the transformers were rectified would be fine.

 

[Jim Davey]

Why not? I must be missing something.

EDIT: Are buzz boxes AC only, that would explain what you mean.

Will this system work with TIG welders too?

I guess so, but you might have issues with the HF, can't see why not but then again it's a lot less hassle to just buy a bigger set.
I only put out a gouging machine 3-4 times a year so I can't justify the cost of a 700 amp dedicated gouge-pack, but as I've got over 40 of these Newarc lumps kicking around it makes sense to put them to work together as and when needed. I think the total cost of the gear to join them was £150. No brainer really.

 

[Kent]

so if you needed to get say near 225-250 amps on single phase could this be so simple as linking two single phase DC inverters as you suggest? I face this a lot as there are very, very few farms on three phase up here. not something I have ever done before so totally green. Are their other implications to consider?

 

[Jim Davey]

Yes, it's pretty easy.

 

[rtbcomp]

Why not? I must be missing something.

EDIT: Are buzz boxes AC only, that would explain what you mean.

.......

Yes, buzz boxes are a simple transformer, AC output.

...........one will be putting out negative while the other puts out positive. At best this will reduce current as they will cancel eachother out but at worst it can damage the transformer.
.........

If AC is 180 deg out of phase they will cancel out if connected in series. If connected in parallel the effect will be the same as connecting 2 batteries + to -, ie in series with a dead short giving rise to maximum current and possible damage.

 

[Jim Davey]

I said it wasn't a good idea

 

[the snooper]

If both buzz boxes are just transformer only you should be able to do it as long as you know for sure your power comes from the sane phase

 

[Maker]

If you have 2 machines with the same transformer inside, connected to the same supply then the phases would be aligned wouldn't they?

 

[Kent]

Yes, it's pretty easy.

great stuff, what sort of coin might I be looking at for what I required after the sets? I take it there is no need for the same inverter sets or max power just put them both as equal?

 

[Shox Dr]

Would it not be a good idea to test both sets to make sure they are putting out what you set it at.

(Good get around by the way never heard of it)

 

[Bill Edwards]

If you have 2 machines with the same transformer inside, connected to the same supply then the phases would be aligned wouldn't they?

Funny, that thought had occurred to me just before I got sight of your post.
It would seem logical, can someone who knows about these things explain if there is a flaw with this line of thought?

 

[Jim Davey]

I do, the twin pot in the remote does that automatically, I could set one to 300 and the other at 100 to get 400 amps out, it wouldn't do my set any harm, but why do that? One would be working harder than the other and it's easier on the operator if they look at the meter on one machine and double it to get an aproximate output, within 10 amps or so at 4-500 + isn't going to matter.