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MIG with Voltage and Current adjustment but no wire speed?

Posted: Fri Sep 24, 2021 11:46 am
by EttieneSA
Hi All
Greetings from South Africa

I recently acquired a mig welder with separate wire feeder on auction.
It didn't come with the inter connect cable so I opened it up to see if I can figure out the wiring needed for the cable. It has a 7pin on the machine and 6 on the wire feeder.
The thing that confuses me is that on the wire feeder there a knob for voltage and a knob for current adjustment, but nothing for wire feed speed. On the power source there is 3 knobs, crater fill voltage, crater fill time, inductance.
It looks like a original label from the factory but judging form the fact that its a chinese machine its possible its labeled wrong.
I had a look on the net and its seems that there are other wire feeders with the same labels.
This picture shows a feeder on the net with the same labels.
Image

I am used to mig machines having a voltage knob or sometimes incorrectly labeled as "current" knob and then a wire feed speed knob.
I haven't connected or powered up the welder yet, will have to test the pins first to figure out the pinout. So I am not able just to play with the knobs and see what happens.
Is it possible that the current knob is actually the wire feed speed, since wire feed sort of determines the welding current?

Thanks

Re: MIG with Voltage and Current adjustment but no wire speed?

Posted: Fri Sep 24, 2021 3:00 pm
by Louie1961
On any MIG welder, the wire feed speed IS the current adjustment. What scares me more on this welder is the ability to set the voltage above 30 volts. I have never seen that before. I wonder if this unit is really not a MIG welder and rather is a submerged arc welder (sub arc). Subarc voltages get that high.

Re: MIG with Voltage and Current adjustment but no wire speed?

Posted: Fri Sep 24, 2021 4:14 pm
by EttieneSA
Thanks for the reply, means my train of thought was correct. Just threw me off as I have never seen it labeled as current, only as wire speed.

The feeder in the photo is not from my machine, just a example. I didn't check if mine state volts or not.
For information what volts would a 500a mig run at about?

Re: MIG with Voltage and Current adjustment but no wire speed?

Posted: Fri Sep 24, 2021 10:17 pm
by Gdarc21
Depends on what you are welding 1.2mm flux core will go up to around 30volt. If you can keep up :) 2mm obviously higher. Solid wire a nudge more.
I believe that wire feeder is a heavy industry shipbuilder, the knobs are so you set it well away from power source. Remotely.
If yours is similar to that one then thats a good find. If it works fine you should be able to weld lotsa heavy stuff, the trick will be getting it set for light duty stuff. General fab will be ok though.
Invest in thick welding gloves. It may feel as useless as self pleasure with oven mitts at first but your hands will thankyou.

Re: MIG with Voltage and Current adjustment but no wire speed?

Posted: Mon Oct 04, 2021 6:27 pm
by sbaker56
Industrial grade units will go above 30V all day long, run even some .045 dual shield or .045 spray arc at the top of the charts and you'll be at or near 30V with that, now make that .052, 1/16 wire etc and you'll easily be over 30 volts if you're going for maximum deposition on thick steel. The XMT 350s we had in welding school would go up to 38V in CV mode set up for mig.

I'm betting on it being some weird mistranslation or mixup for wire speed as frequently wirespeed is described as adjusting your amperage.

It's not exactly correct that wirespeed is your amperage though, but rather that they work in tandem and that within an acceptable voltage range raising the wire speed will increase amperage.

However if anyone here has a machine that displays welding amps or a DC clamp meter, set your wire speed at 600 and your voltage at 17, then set your voltage at 30v and your wirespeed at 350. I guarantee your amp reading won't be higher at 17v and 600IPM than it will be at 30V and 350IPM. Neither are acceptable welding parameters unless you're running some weird diameter wire. Amps is a function of voltage vs resistance, increasing the wire speed tends to decrease resistance thus increasing amps, while drastically raising voltage can have the same effect though it'll likely just burn back on you. For constant current machines like tig and stick welders, they attempt to maintain the same current by adjusting voltage in accordance to resistance caused by arc length etc.