How to mig weld part  1: Power connections

In part one of this how to mig weld guide we take a look at the main power supply connection that comes in to the back of the mig welder.

How to mig weld. Part 1: Power connections

If you are using a single phase mig welding machine more than likely you're going to have a larger 15 amp plug (Australia). This means it your also going to need to have a 15 amp wall socket that will accept the 15 amp plug. All standard power points in Australian households are only rated at ten amps. So if you don't have a larger power socket you are going to need to call up an electrician and get him to come around and fit a larger power outlet for you.

If on the other hand you are looking at purchasing a three-phase mig welding machine or you already have one, you're going to need to either:

a) have the machine power cable hardwired in

b) have a three-phase plug attached to the machine power cable

In my situation here at home I actually have three-phase power and the machine is hardwired into the switch on the wall. These bigger three-phase switches a re actually called isolators. These isolators literally isolate the power coming in to the electrical equipment from the main line.

Start-up current

If you are going to plan on running a bigger machine one area you need to be aware of electrically is what is called the start-up current. The start-up current is also known as the inrush current. This is the initial surge of power that shoots through the wiring when the trigger is pulled on the welding gun. To explain it to you would be a bit like saying go and turn the garden hose on about halfway and put on a trigger squeeze sprayer connection. When you squeeze the trigger down the water will blast out with a fair bit of force. Then after half a second or so because the tap is only opened up halfway, the pressure of the water will eventually settle down to much less than what it was when you first squeezed the trigger. This is how the start up or inrush current works.

Using a generator with a mig welding machine

If you are planning on welding out in the field or away from any mains power, you are going to need to get yourself a generator. A generator runs on either a petrol (gas) or diesel engine that is connected to the electrical generator. You are going to need to work out how much power you need to weld with so that you can make an accurate decision when renting or buying a power generator for welding with.

Some of the bigger wire feed welding units will come attached with a big generator. This then saves the hassle of having the generator and the welding machine as two separate units. The combined units also offer depending on model, main power outlets. This is great for out in the field as you can then run other accessories like angle grinders etc.

How to mig weld. Part 2. duty cycle.