What generator would be good for a mm200?

[Arizona Joe]

Tractor Supply had a Generac 7500(continuous 9350 peak) for $800 last month. That's way less than a good used bobcat with a 2 yr warranty. Guess the big question is are you gonna run it for 40+ hrs a week or bout 4. If you gonna work the thing then you need a bobcat.

A Generac 7500 cannot be compared to a Bobcat 225. Let me explain.

When people say "power", they usually mean "average power" whether they know it or not.

Watt = energy/sec or joules/sec, or J/s
1 J/s = 1 W
10 J/s = 10 W
20 J/.5s + 0J.5s = 10W
10 J/1ms = 10,000 W.

When Miller says 1100 0W they mean 11000Jx30/30s or 330000J/30s = 11000W. That is, 330000J averaged over 30 seconds.
When Miller says 9500W continuous they mean 9500J/s which I take to mean a 100% duty cycle or for as long as you want.

In order to get average power you need to know the number of joules over a certain period of time. If the period of time is tiny, like a millisecond, 10000W has little, if any, practical value.

Now from the Generac spec sheet all is found is:

AC Rated Output Running Watts 7500
AC Maximum Output Starting Watts 9375

What does "Running Watts" mean? Is the machine sprinting for 2 seconds, or is running a marathon?
What does "Maximum Output Starting" mean? How long is "starting"? 1 second? 2 seconds?
In short, the Generac spec doesn't say anything specific. It is vague. Hence, no comparison is possible.

[H80N]

Think we were talking REAL generators, not chinese junk. The generac lineup put out the crappiest of crappy power. Almost don't know where the sinewave is on one of these when its on a scope. good for RV's maybe,,,

Cruizer

we have had generator questions in the past... I seem to remember some discussion of some of the less than "Pure Sinewave"... being dangerous to the welder... taking out boards etc...

I regularly run a Dyn 200DX off of a 1979 vintage 5kw Homelite... but I scoped that long before I did and it makes a very pretty sine...
(genset purchased new)

[cruizer]

Yes the early homelite, and pretty much any unit that was built in the States, that had parts derived out of Japan had a true sinewave characteristic. These were built to last, and designed rather well.

If you look at the genertor, you'll likely find a bunch of Japanese symbols. Todays machines are simply put, crap. You get what you pay for and sometimes that doesn't work either. when I go to an auction, I buy up all the older generators, cause everyone thinks newer is better. I also get a kick out of buying a machine with 6 - 8K hours, while everyone else is buying he same age unit with 1 to 2 K hours at double the price....... hour meters do turn over ya know.....

[H80N]

Was curious...

I remember banter about some of the gensets eating welder electronics???

[Sberry]

This reminds me, I am down to one working generator

[jpence38]

Cruizer,
That is some good info about generators. Never really crossed my mind. Do you know of any manufacturers that are making newer generators, other than the inverter generators, that are putting out power clean enough to not worry about running the smaller machines off of or do they all need to be put on a scope to be checked??

Also, is there something that I can use ( an attachment of some sort) to help clean up the power on the generators that I have. I have been fortunate enough to not have had a problem yet, but I am not trying to sit around till I do. I am hooking up the Passport Plus and the Maxstar 150 STL to it. How sensitive are they?? Thanks

[AwesomeAlbert]

Thanks for the input guys! a miller generator/welder is a little out of my budget, I just bought the Multimatic and love it! Im thinking of getting either a Generac GP7500E, or the Westing House WH7500E. Any body know witch one is a better piece of equipment? Thanks again fellas!


Generac-
http://www.amazon.com/Generac-5943-G...377330&sr=1-22

Westing House-
http://www.amazon.com/Westinghouse-W...6377330&sr=1-6

[Broccoli1]

Thanks for the input guys! a miller generator/welder is a little out of my budget, I just bought the Multimatic and love it! Im thinking of getting either a Generac GP7500E, or the Westing House WH7500E. Any body know witch one is a better piece of equipment? Thanks again fellas!


Generac-
http://www.amazon.com/Generac-5943-G...377330&sr=1-22

Westing House-
http://www.amazon.com/Westinghouse-W...6377330&sr=1-6

http://weldingweb.com/showthread.php...erac+generator

scroll down to post #6

[AwesomeAlbert]

Considering the input power needed to run your machine, I would say that a 3000 continuous watt generator would be plenty. As for the brand, that would depend on your budget.

That's still way too small for the multimatic

3000/240v= 12.5 amps

The Multmatic draws 18amps at rated 150 welding amps Mig and 20 amps Stick

20amps x 240v = 4800 watts continuous so yer looking for a genset that is around 5500watts

So a 5500 watt generator would would be ideal, but as a couple other users stated I'm going to be using other tools and lights on the generator. So I figure a 7500 watt would be more than sufficient. I was just wondering between which of the 2 generators I should go with that I put in the previous post.

[Broccoli1]

So a 5500 watt generator would would be ideal, but as a couple other users stated I'm going to be using other tools and lights on the generator. So I figure a 7500 watt would be more than sufficient. I was just wondering between which of the 2 generators I should go with that I put in the previous post.

Yorkie on welding web uses a generac with good results- that is his 2nd one- first one just too many hours so he bought a new one.

[AwesomeAlbert]

Gotchya, I missed that link on your last posting. Im thinking of going with the Generac, online reviews give the Westinghouse better statistics though

[Precision]

What generator would be good for a mm200?

If you do end up buying the Generac or another generator that has the 14-30 plug you will need an adapter to the 6-50 on the welder/cutter. EVSEadapter.com has some pre wired ones that are reasonably priced.

[Bistineau]

We have a NICE Kohler generator at work, that could easily power Two of those Multi Matic 200's a few grinders, an air compressor, some lights, and a small subdivision all at once with no problem. But it's only 300KW. If you want, I can get the model number for you. Hey, he never said it had to be easily transported. But on the right truck it wouldn't be a problem, even with the fuel supply and distribution center. It has a 500HP Detroit Diesel, 6V-92. Plenty of power for this application.

[AwesomeAlbert]

If you do end up buying the Generac or another generator that has the 14-30 plug you will need an adapter to the 6-50 on the welder/cutter. EVSEadapter.com has some pre wired ones that are reasonably priced.

but the multimatic200 has the fancy MVP hook up, so will that still be necesary?

[Broccoli1]

but the multimatic200 has the fancy MVP hook up, so will that still be necesary?

Yes- the MVP 240v plug is a 6-50
The receptacle on the genset is an L14-30

You'll need a pigtail to plug in to the genset or make an extension cord with the L14-30 on ne end and the 6-50 on the other end