Welder voltage/ watts

  1. Willl Member

    Messages:
    92
    Location:
    U.K. Berkshire
    Does anyone know the voltage of a cebora/snap on 130 turbo at each power increment, or where I could find the information?

    I'm trying to figure out if my generator could run my welder, I thought for ages that it wouldn't have the juice as I've been told about need roughly twice the wattage of the welder, I recall reading somewhere that at the top end the welder needs ~3kw, which is what my generator is rated at. But I realised the other day that I'll only be welding 1mm sheet, and I could get away with having the machine on '1-min', which might make it possible if it will only need 1-1.5kw maximum.

    Any help greatly appreciated.
     
  2. voipio Member

    Messages:
    988
    Cambridge, UK
    A welding set that requires 3kW during welding will require a much larger generator than that. At the very least it will need a 5kVA genny.

    It's partly to do with the need to effectively regulate generator output during the highly fluctuating power requirements during a weld, and partly to do with the high peak currents required to charge the welder's capcitors, though that will depend on the welder type.
     
  3. the snooper

    the snooper getting older by the day

    Messages:
    20,590
    Location:
    Hull UK
    even a non capacitor welder has a huge inrush which the generator wont cope with and if the generator has an AVR chances are it will be fried
     
    skotl likes this.
  4. Willl Member

    Messages:
    92
    Location:
    U.K. Berkshire
    Unless I'm misunderstanding how welding voltages and the like work, I don't think the welder would be drawing 3kw would it? I'm trying to figure out if the power requirements for the lowest setting would be tolerable for my 3kva genny. I don't really want to just give it a go as its the sole source of power for my garage and I don't want to kill it.

    Excuse the ignorance, but how would I figure out if it has an average? I can't recall from memory what make it is, other that it's Honda powered, and it doesn't have any sort of manual. Is it a case of looking for a model number and a Google search? Or just take the cover off and have a look? If you couldn't tell the limit of my knowledge for these is that you put petrol in and magic turns it into electricity.

    Thanks.
     
  5. the snooper

    the snooper getting older by the day

    Messages:
    20,590
    Location:
    Hull UK
    It's an avr automatic voltage regulator, if it doesn't say anywhere then you would have to look for it however if you can find a large capacitor on the generator then that rules out avr
     
  6. Willl Member

    Messages:
    92
    Location:
    U.K. Berkshire
    I'd hazard a guess that it's non-avr then as the throttle is bigger end and floats around a bit, and the speed of the tools is always relative to the speed of the engine, and I can bog it quite easily when the grinder grabs a bit.
     
  7. the snooper

    the snooper getting older by the day

    Messages:
    20,590
    Location:
    Hull UK
    you mean the govenor changes engine speed quite a bit, that has nothing to do with avr, when you demand power from the generator the engine comes under load and the govenor opens the throttle to keep the generator running at 3000 rpm (most small gennys) on a capacitor regulated genny the voltage will fluctuate a good bit more and if it remains bogged down the voltage will drop and stay there, on an AVR unit voltage from the avr is fed to the armature via carbon brushes so if the engine slows down the voltage to the armature is increased keeping the magnetic field constant which in turn keeps the output voltage constant these type of gennys are far better for sensetive equipment that dont handle voltage fluctuation well
     
  8. Willl Member

    Messages:
    92
    Location:
    U.K. Berkshire
    I'm not sure how much the governor has to do with it to be honest, the only control I have other the throttle is the bar which connects the governor to the carb, it's quite sensitive and the vibrations from the genny shake it about a bit. Even running with no load you'll hear the revs spike and dip of its own accord.
     
  9. the snooper

    the snooper getting older by the day

    Messages:
    20,590
    Location:
    Hull UK
    If that's the case it needs repairing it should run at a constant 3000 Rpm with no load with no fluctuating
     
  10. Willl Member

    Messages:
    92
    Location:
    U.K. Berkshire
    It's pretty fudged, though it runs my tools well enough, I just pause when it dips to give it time to recover with any load. Can't really complain about a Honda powered genny for thirty quid though eh?

    To get back to the topic at hand, the bottom line is that running the welder off the genny, even if it has enough power bearing in mind the 'double the watts' rule of thumb, should be avoided as it might break it. Is that correct?
     
  11. the snooper

    the snooper getting older by the day

    Messages:
    20,590
    Location:
    Hull UK
    If it has an avr if not give it a go on low power
     
  12. the snooper

    the snooper getting older by the day

    Messages:
    20,590
    Location:
    Hull UK
    only if its bogging down becuase he is trying to draw more power then it can supply, from the description given the engine isnt running right so could be bogging down due to that, probably doesnt have an avr but cant just assume
     
  13. Willl Member

    Messages:
    92
    Location:
    U.K. Berkshire
    An update on this, I got some pics. Only took 5 months. So this is what the guts look like, hopefully someone knows what it all does.

    DSC_0098.JPG DSC_0100.JPG
     
  14. gt6s Member

    Messages:
    803
    Location:
    Newtownards Co Down Northern Ireland
    I know from my own 57 Lister SOM generator that when you strike the arc you will have little welding current until engine builds speed up to accept the load. Then it will weld.

    Laurence
     
  15. Justme

    Justme Member

    Messages:
    3,087
    Location:
    Pwllheli Wales
    Your 3kva will only be about 2500 watts.

    I use my 210 amp mig on my 6kva genny but only on lower settings doing thin stuff & it really hammers it even with the large diesel engine.

    Once I want to do more than car thickness I use the 15kva tractor PTO powered genny. That does not even slow on full power.

    The difference is usage is huge. On the small genny you can get cold starts & less than smooth welding. On the big one its like being on the mains with super smooth welds.

    PS, I killed the AVR on the small genny using the welder. So converted it back to capacitor controlled.
     
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