welders an run off generators?

[everlastsupport]

Well, the 300 will pull more power. If the generator can hold with AVR 40 amps. You should be fine.

[sschefer]

A generator that is not designed to be a generator for a welder or a generator that is not incoroporated in to a welder like the Bobcat or Ranger are not good choices for running a welder unless you are very critical about the generator that you buy.

Generally, an inexpensive generator (under 4000.00) that has no load/load rpms (wattage ratings) is not the best choice. The RPM of them motor determines the frequency of the phase and at no load it could be as low as 30 cycles per second on some of the inexpensive models. I deally you would like noload/load condition to be at 58-62 cycles per second. Most good gen sets do not actually increase RPM but instead they increase developed shaft HP to maintain a constant RPM.

An inverter TIG requires very little current when it is not welding. The minute you strike an arc the current demand is instantly much greater and the generator will still be in a no load condition. The time it takes for it to ramp up to meet the current requirement will be a period of insufficient voltage and current will rise rapidly resulting in excessive heat and unit failure.

I think if you look at the Miller and Lincoln, they have welders that can be run on generators but they also state the wattage requirement. Ideally, the minimum wattage (no load) should be adequate (P=IxE) to meet the startup input power requirement of the welder. In otherwords, for a 250EX to be run off a generator the no load current needs to be somewhere between 0-100amps. The welder is a 220v and if it ever started with a 100amp requirement you would need a 22,000 watt generator and that's 22,000 watts in the no load. (P = 100x220)

As was mentioned before, you could us the ramp up/ramp down feature of the welder, if it has it, in order to decrease arc start input current requirements but you're playing a guessing game as to wether the generator can ramp up quick enough and where the upper end of the low limit would fall.

I've left out a lot of the particulars because this post would be way to long to read if I detailed it all out.

My advice would be to buy a welder generator and leave the inverter in the shop. Besdies, TIG welding outside is a hard way to make a living. The setup time eats up all your labor profits and people just won't pay you to do it.

[footboarder]

Years ago I worked near the film crew for 'Runaway Train'. The cycle was so important to them that they welded rigs on the side of the locomotive not visible to the camera so they had platforms to mount their own generators for the moving scenes lighting. These generators had a 'cycle' control and maintainer. This was so important to the film crew because the cycle affects the temperature of the lights (Kevins). This in turn affects the color (Techicolor) as to how the film (negative) reads it. I imagine a rectifier machine is not using DC only. Especially when it is a AC/DC machine. Even a straight DC machine may have controls on the AC side that are affedted by the 'cycles'.