GTAW Process: Proper Wiring
After securing the appropriate TIG welding PPE to be able to safely weld, the next step is to prepare the welder station. To get started, the power supply must be properly wired to input volt and amp requirements of the TIG welder you have purchased. It’s actually cheaper to buy a welder that matches the power supply that you already have. But in a home garage or small shop, the correct receptacle may not be present that meets the wiring codes for a welder. An electrician who knows and understands the NEC section 640 should be hired. Wiring requirements for welders are much different than for appliances. De-rating is allowed to match the duty cycle of the welder, and breaker requirements are different as well. Welders are wired differently as well. For example, a welder running on single phase 220/240V power requires only two hot wires, and a ground wire. No neutral wire is used.
A 3 prong NEMA 6-50 plug is usually recommended and is the standard plug for most welders. Depending upon your existing wiring, this may be a considerable initial expense. Consider having an extra outlet or so for your welder or additional purchases put in at the time the electrician is on site to reduce additional costs later. An outlet every 25 ft is a good starting point. If not, make sure it is centrally located to where most of the welding will be done. Extension cords for welders are not a good idea. The welders should be plugged directly into the outlet whenever possible. Note that many TIG welders have an additional grounding requirement to help reduce issues with High Frequency interference. This usually requires a second bonded ground that is connected to a ground wire directly to a copper or steel rod driven into the ground that is connected to the rear of the machine via a separate cable. Keep in mind, a licensed electrician should always be consulted and codes followed.