Novice in dire need of help!

admin

Hi there!Im a newbie from the UK and a little un-wise to the ways of welding so be gentle!I want to start practicing welding after buying a little hobby gasless mig and wondered what size generator I would need to buy to run it as I have no power to my shed down the bottom of my garden!  A 100metre+ extension lead would be required to power it from the house!!  so not very feasable I know!The mig I have is only a sip migmate and the maximum amps is 90 I believe.  A local shop tells me at least a 4kva generator is required, but I can only really afford a 3.5kva.  Any suggestions???All help appreciated!
Reply:I would check with the manual or the supplier if nesacary to see if it tells you the input voltage and amperage needed for your welder.Aside from that more is always better when it comes to generators.I have a 180 amp welder that only requires 20 amp breaker,because it is an inverter type,which is fairly new technology and works beautiful.If you do decide to run some power from your house down to your shed I would suggest a 30 amp breaker and #8 gauge wire for the 100 feet or so you require.It may be alot cheaper to do that than to buy a generator.Nobody moves nobody gets hurt(safety first)millematic passportmiller 375 plasmacutter
Reply:here is some info I found from the manufacturers website.Input voltage : 230V Fuse rating : 13 amps Current range : 25 - 90 amps 2 Power settings  Duty cycle @ 20% : 55 amps Open circuit voltage 18 - 24  Insulation : Class H Protection : IP 21 Wire sizes / Approx weld thickness : 0.8mm - 4.0mmHope this helps to get an answer to my query.  I really need to run this from a generator cause my folks arent too keen on me running a cable from the house to the shed!  Not to mention the electric bill!!!Matt.
Reply:Matt, a 3.5 KW generator should work especially if you don't try to run the welder at max. settings.  Small generators and welders dont always work together well.  The generator engine will bog down and feed the welder low voltage and frequency if the welder demands too much current.  The electric bill isn't that bad for a welder.My angle grinder is my best friend!
Reply:Well my welder only has a high or low setting, so I guess in order to run it in the "high" mode I would be looking at buying a 4kva generator to get the best from my welder or am I wrong still?
Reply:The fuse blows at 13 amps.  .220KV*13Amps=2.86KVA.  The 3.5KVA generator should do you just fine.
Reply:I'm with 76GMC, a 3500 will do you fine. Just make sure it's a 3500 run and not surge/peak. But back to the household electrical thing. This little welder ain't going to run up any electric bill any more than a toaster or coffee pot. Compare that to about a half gallon and hour for fuel and you'll soon learn who can produce juice cheaper, you or the utility company. A welder like yours will cost you a maximum of 30 to 50 cents and hour (depending on the pennies per KWH in your area) with the trigger pulled and burying wire as fast as it will feed. A generator will cost you a half gallon an hour whether you even touch the trigger or not.So knowing that, generators are a wonderfull item if you can't get commercial power, but not a viable alternative if you can.
Reply:Thanks for the help guys,so is there a mathmatical way of calculating how much power my welder requires?  Just in case I upgrade my welder in the future so I dont have to go out and buy an even bigger generator!  Im watching a few generators on ebay at the moment that are very sensibly priced but vary so much in power.All help greatly appreciated!
Reply:I vote for a heavy duty extension cord.  As a teenager I ran a 220 volt stick welder from the house splicing into the oven circuit.  You will need to invest in an industrial rated power cord and plug conectors.  A welder uses less juice than the oven.
Reply:so is there a mathmatical way of calculating how much power my welder requires?
Reply:racingdrivermatt asked, "so is there a mathmatical way of calculating how much power my welder requires? Just in case I upgrade my welder in the future so I dont have to go out and buy an even bigger generator!" The problem is not in determining the worst-case power demand of your welder, it is in determining the true capability of available generators to supply that demand.  Other posters have commented on the "specsmanship" that goes into the claimed power output of home generators.  I'm reminded of the "1600 PSI*," pressure washer I purchased and got home before I read the fine print that said "*equivalent with our wonder oscillating nozzle," and the " -80"  home wire welder that could only put out 60 amps at 20% duty cycle.I'm struck by your concern about the electric bill.  I suppose there are many reasons to want to get a generator, like total portability for remote jobs, but please don't make the decision based upon a supposed lower cost of power.There are several ways to look at the ECONOMIC aspects of buying a generator vs. running utility power to your shed.  For starters, just ponder the relative efficiencies of power generation (including distribution losses) by your electrical utility using power plants engineered, optimized, and operated by experts to squeeze out the last thousandth of a percent of efficiency using the cheapest fuel and benefitting from the efficiencies of scale compared to power generated by a home power plant designed for lowest purchase price, ease of use over a wide range of loading conditions using fuel you can buy at the local petrol station (is that what they are called there?).  Your typical utility power plant operates at about 60% efficiency, (a number I think I read in an article on alternative energy in IEEE Spectrum magazine), while a typical automobile (with an engine much more optimized for efficiency than a home generator) operates at about 30-35% efficiency, from fuel input to power at the wheels.  Your generator is going to be even less efficient even if it could be used 100% of the time.  In reality, it will be used at capacity only, about 10 to 20% of the time, even if you are very careful to start it up only after you have completed preparation of your weld.  Starting and stopping the generator for each weld would lower efficiency even further due to operating at lower than optimum temperature much of the time.  I would bet that a proper analysis of generator amortization and realistic fuel consumption would show that you will be paying MUCH more per kilowatt-hour for home generated power than for utility power per hour of welding - probably many times more - not even considering amortization of the generator purchase and generator engine maintenance. To compare up front costs of PROVIDING home generated power vs. utility power you have to compare the cost of running power to your shed with the purchase price of a generator of adequate capacity for present and future welders.  (If you are like most of us, you will want more welding power pretty quickly.) Figure out the cost of running power to your shed.  100 meters is a very long run for an extension cord, but quite possible.  At that length you would be tempted to leave the cord in place instead of paying it out and winding it up for each welding session.  That would invite disaster if someone stuck a shovel into it or ran a vehicle or garden equipment over it too many times.  However, if you welded up a hand cranked or powered reel, the task of handling the extension cord could be manageable.  The cost of 10/3 AWG (American Wire Gauge - how do you size wire there?) type SOOW heavy duty, rubber covered cord is about $1 per foot here in a 250 foot reel (77 pounds of cord).  I imagine you could get a single length of similar cord 100 meters long there at comparable cost per foot, and you should use a single length of cord.  The supplier recommends 18 amps max for 250 feet of #10 AWG.  Probably pay another US$30 or so for two heavy duty cord connectors.So it looks like you would be able to run power in your shed for about half to 1/3 the price of a new generator, assuming you already have a suitable 20-amp outlet in the house.  Of course, salvaged cord (I have a 100 foot roll of like-new 10/3 very heavy duty rubber covered cord in my basement that I picked up for $5 at a salvage outlet, but that was really lucky), or a used generator would modify the comparison.So, my conclusion would be that if you decide to go the generator route, it should be based on considerations other than setup or energy costs.Have fun.awright
Reply:Thanks for all your help guys,I take the valid point of cost to run a generator, however it is my intention to use the welder infrequently and not for any business or heavy usage at this point so I really odnt mind filling up at the petrol station a few times!I got lucky today and purchased a brand new 4.9kva generator for next to nothing! So im sure that this will power my welder with ease?  I'll give it a try tomorrow (20th April) and let all you guys know how it performs.Matt
Reply:Well i tried it tonight and all i can say is that you wouldnt know the difference from using the generator to using the mains to run the welder.  So problem solved!Cheers for all the help guys!Matt
Reply:Here's anothe question i can test you guys with.Got my welder set up using my newly acquired generator and it works **** well.  however getting on to a health/safety issue here but, I have a solar powered auto-darkening welding helmet and the adjustment dial reads from 9 through to 13.What setting can I safely use on this helmet without burning my eyes out, i did that once before a few years ago with a standard welding mask with a crack in it and ended up spending the night in hospital!!!  so one bitten twice shy really!The reason I ask, is that i find it very hard to see the work im welding on and I tend to drift off the weld line!!!!
Reply:Mines a fixed 10 and sometimes it's too dark, sometimes too bright, soo mess around with the 9/10/11 ranges. The surrounding lighting conditions have a lot to do with visibility too. Try not to have a light shining right into your hood from the backside.
Reply:But set on 9 im not going to burn my eyes out am I?  I really dont want to run that risk again, its too painful and scares me!!!
Reply:Modern auto-darkening hoods have full shade 14 to UV at ALL times, even when not turned on.  The adjustable shade is only for visible light; put it wherever is most comfortable for you and your welding conditions.  I'm on shade 9 most of the time.This is an entirely different issue than a cracked lens, which lets UV in through the crack!