MIG Wire Speed

[Marty]

Hi Andy,

I am just learning to MIG weld. In my training manual, the instructions specify that I set the welder to ~100 V and the amperage to 75 amps.

Can you tell me if there is relationship between wire speed setting and current generated? In other words, does setting the MIG machine for 300 ipm correlate to a specific current?

I've searched everywhere that I can think to find this relationship to help me set my current value. My specs never state "set wire speed to ...."

Out of curiosity, why do MIG power source display wire speed instead of current if specifications call out for a specific current level?

Thanks for the help.

Marty

[hankj]

Marty,

Welcome aboard.

What kind of welding machine are you using? GMAW (MIG) welding arc voltages run in the neighborhood of 20 - 40 volts. I can't imagine a CV machine with a setting near 100V.

As to your wire speed/current relationship question, the wire burn-off rate (speed) determines how much welding current is needed, so there is a direct relationship between wire speed and welding current. There should be a chart for your machine which shows the current/voltage curve and will allow you to interpolate the approximate amperage based on the wire feed speed.

A sort of "rule of thumb" for .030 solid wire electrode is 2 IPM speed = 1 ampere of welding current. Based on that number, you'd want to set the wire speed at 150 IPM for 75 amps.

Hope thih helps. I'm sure you'll get more feedback on this.

Hank