Generator question

i might be able to pick up a portable generator pretty cheap. Here's the info and the question.
It's an 8000 running watt , 13,500 starting watt generator. 15 horsepower. With a 220 volt 30 amp outlet.
Can the outlet be changed to a 50 amp, 50 amp breaker. I'd like to use it to run a Lincoln 225 amp buzz box welder. Would this work ?

 

8,000 watts, at 220vac, is a draw of 36 amperes. How many amperes is your welder rated at?

Before even considering anything else, I would not add a higher rated breaker on a circuit that is rated much lower. If you did, your protection just went out the window.

 

What matters is how much does the Cracker Box draw in the most common setting you will use. Then again you can't get apples from a turnip patch. Just another way of saying you can change the breaker but that doesn't increase the output, it'll just burn up the Generator if you load it up past a given current at a set voltage. The breaker is there to protect the wiring and the winding's of the generator.

 

Don't change the breaker. HKuser said it...you'll just cook the generator.

You may be able to still use the welder if you keep the current below 125 amps with short duty cycles

 

To run a Lincoln 225 at full power its going to need around 55 amps of utility power.
That generator running that welder will only be able to satisfactory produce around 120 to 130 welding amps no matter what breaker you put on it.
If you really want an engine driven welder build a vehicle based alternator welder like I did.

You want to know what the sad thing is, your 15hp generator can only produce around 120 to 130 welding amps, but my welding alternator with a 5.5hp honda motor can produce about 100 amps.
When I upgrade to a 13hp engine I should be able to make 180 welding amps easy.

Actually to run that Lincoln at full power you would need something like my 30hp V twin 922cc 17.5kw generator.

That welder should be able to run near continuously at 125 amps. The generator may not.

 

Don't know about the genset you are interested in, but most of the new stuff, since the price of copper went thru the roof, depends on a higher temp rated insulation on the wires in the rotor and stator to use less copper and run it at a higher temp. The old standard was for 20,000 hours of operation at the design life of the wire insulation and operating the winding 10 C hotter than optimum would cut the expected life in half and decreasing it by 10 C would double it. Each class of wire insulation had a design temperature limit and changing from type A at about 105 C to type H at 180 C allowed you to raise the operating temp of the motor by about 75 C and thus use less copper in the windings. Then came the game of redefining the rating by using the shorter design life at higher temps and call it starting load. A lot of companies, both domestic and import, play games with the numbers and end up with a unit that is no longer designed for 20,000 hours at anywhere near the stated load, and that stated load is under perfect temps, perfect loads, constant load, totally clean environment with perfect humidity, etc. Then again a lot of manufacturers out their either don't follow the rules or don't give a da**. A good portable welder, which has to meet some challenging loads, isn't cheap and is seldom worth repairing as the cost of the parts is very high.

Cutting to the chase, you have two choices, you can spend a lot of money for a properly designed unit with a designed 20,000 hour life of the electrical unit, power unit is a separate issue, and have a long life if properly used, or you can cut corners and spend as little as a few hundred dollars for something that has had so many design "optimizations' that the realistic life at the stated power may be a few hundred hours and at any overload may be less than that. The stated ratings of most electrical motors and alternators has become a farce, the old air compressors stated that they were 1 HP units and drew 15 amps of 115 V power under load, the new ones, draw 13 amps and state that they are 3 + HP and I don't think that the laws of physics have changed in the last 30 years.

 

I read up on a website about welders that said my welder could run effectively on an 8000 watt generator with a 50 amp breaker. And the one a friend has is a 30 amp outlet, I couldn't find the actual breaker, but I had limited time to really look it over. I never really knew outlets had an amp rating, but it does kind of make sense. I may still get the generator, but not for my welder purpose. Electrical stuff just doesn't compute well in my brain for some reason, I can wire the switches and outlets and hook up the breakers , but the rest of it just won't kick in. Thanks for all your help.

 

I fully agree with Duane.
Ideally the best is to have a welder engine unit engineered of it's own design .
All too often people try to run too much off their generator and burn both up, I saw it mostly with air compressors .
With them as well , your better off ,a gas engine operated unit .
Ratings on the electric motors are misleading , It's obvious that something is wrong when they avoid listing pertinent information on the motor . 750 watts per horse . amps X volts= watts
Never use an extension cord on an air compressor, if you can avoid it , ( Wire gage sizes go from small numbers like 4 being a large wire you would use for welding cable, to 18 gage a very small wire you might use for a lamp.) the larger the wire the better , it handles amperage best. But If any thing use a longer hose .
In some cases I have put a second tank on the other side of the shop, and it also acts as a moisture trap , beyond providing the burst of air some tools require. By the way , moisture traps don't work directly attached to the compressor tank, they need to be at least 20-30' away on an air line . If your in a particularly humid atmosphere , I recommend a coiled length of 1/2" soft copper tubing coiled in a bucket of water before the filter/moisture trap.
Secondly I have a permanent hose at the bottom of the compressor tank drain with a permanent blow gun on it to remove the moisture from the tank regularly ,that air is used to sweep out the shop . the dryer you keep that tank the longer it will last.
By the way Husky provides a high out put quick coupler that exceeds the out put of the common 1/4" amflo every one has been using, without going to the big half inch job they use on 1" impact wenches.(those tools still need their large couplers) I've been switching all of my every day stuff over .
Good to remember too that there are electric tool substitutes to most air tools, so it is not necessary to run the air compressor all the time. Granted they are not as strong, and you dare not run these standing in water, but they are handy just the same.

 

An outlets amp rating is for continuous use.
Welders are not continuous use machines.
For example I have a miller dialarc 250 that is recommended it be put on a 100 amp breaker, but it has a standard 50 amp electric range cord from the factory.

When you generate welding power as 3 phase and only at the voltage required you need a little less than 2hp per kw.
Generating electricity in 3 phase is about 11% more efficient than doing single phase. Then you have losses stepping the power down to welding voltage which generates a lot of heat due to the unbalanced welding transformer.

You can always power factor correct your welder. When I power factor corrected my tapped transformer welder it drew 2 less amps.

I run my air compressors on extension cords but mine are 240v, soft start equipped and power factor corrected.

 

Problem with welders is that they are playing the same numbers game on rateings. Welded hard surface used to resurface rock crusher jaws when I was in college as a part time job. The welder was putting out its rated power with probably at least an 85 to 90 % duty cycle in the weld. Wire fed, gas shielding, welded at least 3 pieces and go from one to the next to minimize heat distortion. If you look at a Harbor Freight unit, it calls for a 170 amp welding capacity, but states that it has a duty cycle of 20 % at 110 amps. Thus it has to cool down at lest 4 minutes out of 5 to prevent over heating at about 2/3 power. I would not really know what it would take to power a welder, need to know current used in weld, duty cycle.of weld, what kind of reactance load it puts on the generator, etc, or try it and see what happens or be very conservative with the generator rating.

 

As someone who has made their living with portable welders, why go to all the BS of a gen set to power a little 225 tombstone welder? If you want a portable welder just buy one. I've never understood all the hassle some folks go to with alternators turned welders, generators to power welders, ect. Buy a little Bobcat welder for $1,800-2,000 and be done with it. You get the added benny of having a genset as well. MANY of the Bobcats or Lincolns of this size generate up to 10kw of power. They can be run on gas, converted to propane or had with a diesel engine. Problem solved.

 

I've converted a couple of Bobcats over the years, Like you said they run just fine.

 

That would be the smartest thing to do. But Ive already got the welder , just need to get power out to where I would use it. I don't use it enough to be buying a new one. The generator I'm talking about might could be picked up for 200 or less, or a few small trades. Just trying to get by on the cheap.

 

My alternator welder makes almost as much DC welding power as a smaller to mid range portable premede welder for a fraction of the cost of even a used portable welder.
Plus my alternator welder is anti proprietary. You can use anything you want to build it or fix it. Unlike for example most miller machines (not just their portable engine drive welders) made with in the last 20 years. They all have circuit boards in them that become really expensive or impossible to get as time goes on.
This is part of the reason you still guys using really old machine from say the 1960s to as far back as the 1930s. A reliable machine a welder can actually repair it them selves and it doesn't require any thousand dollar proprietary circuit boards.

Alternator welders are not intended to replace the portable welders professional full time welders use. Just everyone else that could use a simple engine drive machine but the cost and weight of a factory made one is too much.
Plus you know the whole self sufficiently thing.

Also all the really good deals on engine drive welding machines I have found were too good to be true. If you find a really good deal on a welding machine expect to be asked to wire money over seas.

 

Pipeliner Lincoln. No battery needed, hand crank and magneto. Always ready to go.

 

That's what sets on my truck. A 1972 model. Another is on a small trailer in the tractor shed.

 

You are further ahead with an engine driven welder ,both for it's portability and the fact your not dependent on the grid and driving up your electric bill in the mean time.
My little 140 amp Dayton Tecumseh engine welder provides a 15 amp 120 and 240 volt outlets intended for disk grinders and such you'd be using in the field .
Taking care of the engine is about all the care it needs ,and is very dependable .
I also have MIG, TIG, and 3 stick welders ,including oxygen and acetylene ,ect.....
I've learned long ago about the limits of any equipment and not to push things to their ratings .
Even down to soldering guns , pushing the limits severely reduces the life span.
The only thing disappointing to me now days is, my hands are not quite as steady as they were years ago .

 

Electrical power from the utility costs 10 to 20 cents a kwh. If it costs much more than that you should probably reevaluate where you live.
To generate power with a diesel generator would cost between 50 cents to $3 per kwh in fuel alone. Gasoline costs even more.
Then when you count oil changes, filters and maintenance it's even more.
So don't buy an engine drive welder to sit next to utility power thinking it will save you money.

 

Just don't forget to have a baffle box for your generator.