View Full Version : How to test the output of a welder
03-25-2005, 12:40 PM
I would like to test the output of my welder to see how many amps I'm actually putting out. Is there a way to test a Mig and a Tig?
03-25-2005, 12:50 PM
You can do it with a clamp on AC/DC ammeter. I use this one:
03-26-2005, 10:11 AM
Using a clamp on meter doesn't really tell you much because you have no way to load it properly. Some people try to do this and dead short the machine but it doesn not accurately simulate a welding load ( because arc voltage drops to zero in the dead short ) . Inside a load bank there are numerous resistive coils that can be "loaded" on the welder to simulate a load at typical welding arc voltages
The only way to do this is with a load bank. EVERY welding service facility in the universe will have one . It takes less than 5 min to load bank a welder. You can load bank both CV ( MIG etc ) or CC ( stick / tig ) machines
Using a clamp on amp meter will only tell you what output you are welding at, not what the machine is capable off under a load. You can't accurately do this without a load bank
If you could service shops would be spending thousands of $$ on load banks .
03-26-2005, 11:57 AM
So I guess the question should be, do you want to know about what you are running at during some of your more common operations or do you want to know its absolute maximum value at any given setting?
More pratical knowledge would be to know a few of the "about" numbers. For that a clamp on is close enough. Most clamp ons have a peak hold setting but that really isn't a true representation. Don't use that. So you need a clamp on and a helper. Set up one of your more common welds or one that you are interested in, clamp the meter on, zero it out, have you helper hold and watch will you draw a smooth arc, they state the value when it comes off peak. Record that setting and value. Move on to the next test set-up and have some fun. Draw short arcs, long arcs, do extreme settings and any other scenario you are curious about.
Keep in mind digital meters are sensitive and will have a hard time ever stabilizing to exact values under these conditions but it matters little for these purposes. Also for mig any minute trigger currents may deduct from actual readings as well as the fact that pulsing won't give pure readings and any welding current will be constantly varying somewhat. Knowing this will help your 'helper' grab an average a bit quicker.
03-26-2005, 08:16 PM
clamp on AC/DC ammeters are expensive
the lowest one ive seen that will work for my use is $50
its a craftsman