welders an run off generators?

[performance]

Any welder generator built in the last few years should be fine. Older ones may not.

Still, a lot of discussion can be found about generator quality on the net. But if you'll see companies like Generac, you'll find that they have units that they admit are not acceptable for electronic items. They sell a higher priced unit that they say is "safe".

[Jeepster0000]

Ray and Mark,
Thank you for the fast replies, I am looking at purchasing the TIG welder in the next month or so. I have been reading a lot about the power output of the bobcat vs trailblazer vs ranger. I do a lot of welding off the bobcat, and have had no issues with it, so I just want to expand my capabilities with the TIG.

My welder / generator was built in 2001, is that too old? Now the big question, should I keep the bobcat or sell it to get a trailblazer or bobcat diesel? Or, should I keep the bobcat, and run it off that? Remember money is an option!

Thanks
ADAM

[everlastsupport]

You have a couple things to deal with when running a solid state welder off a generator. In rush current, ramp up and a clean running sine wave.

If the unit you have is 8500 watts, that's enough power to run a 200 amp TIG (35 amps of power). If your unit has a clean sine wave, but no AVR, you can start the amp low and ramp it up via the 4T or foot pedal. Automatic voltage regulation (AVR) is key in starting the unit, but a good sine wave is more key far as damage to the power supply.

Call Miller and ask if the Bobcat will run their new solid state units. If they give you the go you're probably fine.

[Ray]

Jeepster,

If you do contact Miller I'd be curious what they’re response was.

Ray

[Jeepster0000]

I did contact Miller. He said that my year of bobcat will be good to run the miller dynasty 200 and any other solid state units like a plasma cutter. Though he did stress that I should not run the dynasty 300 off of my unit.

But I think the Everlast Tig should run great

[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.