Because the tap welding machine is easy to use, but the transfer switch transformer is prone to problems. It does consume electricity.

Inverter welder 250 or 300 3 15 can meet your requirements, and you can also buy 4500! But I suggest that you must buy a welder made in Chengdu, made in North China and made in China, with good quality and performance. Some are really cheap, but don't buy them. The failure rate is too high. They are all made of old parts.