Has anyone driven an arc welder with an ST5 ?
I'm trying to determine what size of a welder I can drive with the 240V outlet.
Would the welder be considered an inductive or a resistive load ?
Do welders have an amperage spike when an arc is struck similar to an electric motor starting?
PS: My ST5 is driven by a 6/1 with a theoretical max. output of 3kw (I haven't tested the limits yet)
cheers,
veggie
I have a lincoln AC 250A buzzbox. It blew the 30 amp breakers in my shop repeatedly at 120 amps setting. After changing them to 40 amp I'm OK up to 135 ( highest I have used so far) . Welders need a lot of juice .
Ditto on the Craftsman buzzbox I have, except I went to 50 amp breakers. I used 50's just because I had them lying around,
not because I thought I needed them.
Ron
I have an old lincoln 250 ac dc and I believe it is fused 75 amp, but I can run it with my st5 up to near 150 amps. The big amp spike is starting the arc or especially when you stick a rod to the metal. Merely flipping the switch on with no load on the welder doesnt even seem to register but when you strike an arc the 10-1 snorts a bit.
Arc characteristics seemed ok but it was just a short test on a scrap plate.
Thanks,
From what I read above, a 3kw ST5 would not be able to properly drive a stick welder. :(
I was hoping to be able to weld up to 3/8 material with a small arc welder.
There are some MIG welders which can run on lower voltage 120v, 20 amp outlets.
From what I understand, 3/8" plate is too much for a MIG welder.
veggie
Yep I have one of the low end 110 volt migs, the limit is 1/4 inch stuff. Of course I suppose you could do a couple passes.
Ron
Definitely, in a prior occupation I ran a mig that burned 1/16th wire on 440 3 phase, that beast would weld just about anything.
Ron.
one of the biggest surprises i have found in a small 120 volt wire feed is the hobart 120 mig
running .030 E70-06 wire and co2 that little bastard will weld like a much larger welder
i have used many of the small lincolns and the harbor freight types all of which i was really
disgusted with
i bought the little hobart with two blown diodes for 100 bucks iirc from a guy on craigslist
replaced them with oem diodes at 36 bucks a pair and put it to work with .023" wire
it did ok, but was really more on a par with the lincolns
when i changed to .030 and co2 it was like kicking it up 20amps and into the realm of a useful
welder.
if your 6/1 with st5 can put out 20amps at 120 volts you could do much worse than a used hobart 120mig
just wish i had a decent 50amp 240 volt supply, i would move in my trusty linde 225 and there is about nothing
i would ever do that it isn't up to welding, right up to spray arc.
but sadly it takes a bit more than a 6/1 can put out even on nitrous
:)
bob g
Just stick with the 7018's and a good buzzbox and a little rod heater. KISS principle. We are not all going to be high end ticketed welders. Just messing around and want to weld up some channel iron once in a while......
Tim
good point and probably safer for the beginner than a mig is just using a stick welder
although you might wanna work with 6011 which will give a very sound weld, albeit hard to chip between passes
bob g
7018, store em hot, dig em in deep and pour on the heat. love it.
T
thats just the problem, you got a limited amount of heat with a 6/1 and st5
bob g
My 10-1 running at 900 rpm drives enough out of an ST5 to run a really hot 3/32 7018 so might be a bit iffy with a 6-1, but should run a 3/32 6011 with no problem. The flywheels will carry you through the arc starting time without problem and the continuous output should hold the running arc current without too much sweat.
Quote from: Crofter on January 06, 2010, 08:49:28 AM
My 10-1 running at 900 rpm drives enough out of an ST5 to run a really hot 3/32 7018 so might be a bit iffy with a 6-1, but should run a 3/32 6011 with no problem. The flywheels will carry you through the arc starting time without problem and the continuous output should hold the running arc current without too much sweat.
Thanks Crofter,
I picked up a small 120 Volt TIG machine. Can do 1/4" and 3/8" plate if doing 2 passes.
For making brackets and small tacking jobs it should be ideal.
I will report back after A] I learn how to use the darn thing :D, and B] Do a few good test welds.
Fortunately I have the help of the welders at work for advise.
This raises another question regarding 120 volt welders.
How concerned should I be about the other (unused) leg of my 120 volt supply from the ST5 ???
veggie
If you want it hot, I'd wire the two legs together. Until we figure out the BS ST mod, It will be VERY unhappy about pulling that kind of load on only one side.
Quote from: bschwartz on January 06, 2010, 08:31:22 PM
If you want it hot, I'd wire the two legs together. Until we figure out the BS ST mod, It will be VERY unhappy about pulling that kind of load on only one side.
Perhaps a stupid question.....but here goes..
My junction box has two 120 plugs (pulls 120 from each leg in the dog house) and one 240 volt plug.
Is it possible to make make a "Y" cable for use with my welder that plugs into both of my 120V outlets and in effect, wires both of the 120 legs together?
veggie
It might make funny groans but it it will be OK to 20 amps. If you need more power rewire your head for full output at 120v . directions at utterpower. Easy to do. Then you will have 40 A @ 120. It is either in series or parallell . Can't be both at the same time. Possibly a S/P switch setup could be invented for this.
Sounds like you are going to have fun!
Tim
Parallel the windings Jens. Not series. You can have 240@21.8 amps , that is 2 @120 volt legs 180 degrees out of phase to each other. That is series connected. 120 or 240 volt loads supported.
OR you can wire it in parallell for 43.6a at 120v. 120v loads only up to very high current levels. No 240v loads supported.
T
If you are trying to use the head on 110 220 you are only going to get half your
output switch to 110 only to eliminate growl and get your max output.
Potter
If you wish to use both legs of 120 they must be hooked the same polarity. The Y connector would be a dead short across 240 if the other ends of the 120 legs are hooked N to P for series connection.
You can pull 3 KW from one leg of an ST 5 with a 6-1 but you will be 500 watts over the rating for that leg and voltage will most likely be very low. Hook up in parallell and you produce 3KW at 1000 watts under each legs max rating and both welder and generator will be much happier!
The little "lunch box" inverter welders would be the real trick. With no transformer losses they make very efficient use of limited input power but they are pricy!
Jens,
With my now VAST experience pulling apart my ST gen head (haven't put back together...) may I suggest you open yours up, find the center tap, and split it and add your own second line. Then you could parallel the coils if you wanted to.
Here's a better view of what I'm dealing with...
The ST5 is already wired to a sub panel with 240 and 120 outlets.
I prefer not to disturb this layout because of the other uses I have for this machine.
Rewiring the whole thing for 120 would mean upsizing the wire, plugs, breakers in the receptacle panel.
The pictures below show the wiring layout and how the 240 and 115 were separated.
(Note: The fuse blocks have since been replaced by breakers)
So....can I get get 120v 30A power without rewiring my ST5 (or the receptacle panel) by combining the two 120 outlets using a "Y" cable? Or will this create the dead short as crofter pointed out?
For TIG welding, my machine requires a 23A, 120 volt supply.
Any other options?, or am I s#*% outta luck ?
veggie
IF and only IF your head is wired as the diagram below, you should be able to make a Y cable.
If one leg of your head (say blue wire and one white taped) is U1 and U4 (or U3) and the other leg (red and white taped) is U2 and U3 (or U4) and currently U3 and U4 are the white taped wires, then connecting your red and blue wires (U1, U2) would put them in parallel.
Can You check for continuity to verify the separate windings?
Veggie, If your connection to the panel is to remain intact, then you have no choice except to use a 240-120V step down transformer. This will cost you about 7% efficiency if you can find some suitable toroid transformers.
But since the welder will totally use your ST's output, bringing out the wires to a switch box so that you can DISCONNECT the line to the fuse box, and create 120V just for the welder, might be a better solution.
BruceM,
Not trying to create an argument here... :)
But are you saying that bschwartz' idea for the "Y" cable would not work?
I need to be clear on this.
thanks,
veggie
Hmmm. Rethinking my earlier post. If you have U3, U4 tied together, connecting U1, U2 might put them out of phase (wrong terms I'm sure) with each other. On the St head, when bridging for 120V, they usually connect U1, U4 and U2, U3.
Although parallel, they would be backwards.
Maybe a Y cable would be bad.......
Now it's clear.
Thanks guys.
I like the idea of bringing the ST power into a switch box and then branching to the panel or the welder.
veggie
Jens, now you're just bragging ::)
I believe it is seldom a mistake to buy a quality product! I bet you wont regret it.
I do own a ST12 and it has been good so far.... But I only use it as needed (Powerfailures)
also some fuel experimentation. I will say they are inexpensive.... But a bit of a crapshoot
and a likely diy project.
Rob
Veggie, Yes, I like Bschwartz's approach, I'm not very wordy this week as reading is a bitch right now.
Quote from: BruceM on January 07, 2010, 07:18:39 PM
Veggie, Yes, I like Bschwartz's approach, I'm not very wordy this week as reading is a bitch right now.
Bruce,
OK now I'm confused again (not hard to do ::) ).
Bschwartz said that his suggestion for the "Y" cable might not work.
The easiest fix for me is a "Y" cable.
Will it work or not ? :)
veggie
Veggie, what you need is a switch box that lets you:
1. Switch your ST head wiring between 120V (parallel) and 240V.
2. Disconnects the 240V connection to your main power panel when 120V is selected, the 120V being just for shop welding power.
This is going to take some fancy ganged switches or perhaps some DIN rail circuit breakers which can have their switch levers ganged via music wire. I don't know the best way of doing this- maybe Shipchief would?
There is no doubt that this is doable following the wiring diagram provided with the ST head.
In this case, careful labeling of the wires before extending them from the genset to the switch box should eliminate most chances of polarity reversal. You will be extending 4 wires (one pair for each 120V coil set), your switch box will put them either in series (240) or parallel (120). A temporary inline fuse for one winding set for initial test is a good insurance policy.
The attachment shows a switched setup- egads, it takes 6 switches, which would have to be ganged and break before make types.
Plan B- make up a cable from the 4 coil wires that plugs (Sermos?) into one of two sockets; one is for your existing 240V feed, the other for your 120V welding supply. Each socket would then make the proper winding configuration.
Plan B is a lot cheaper and simpler.
i think you could also use a reversing contactor set to allow for the interconnections, with a simple flip of a toggle switch
a reversing contactor is both electrically and mechanically interlocked so that there is no way of getting both cross connected
they can be had fairly reasonably used and surplus off of ebay, although the large sizes can be quite pricey.
i got a schematic somewhere outlining this system for 60 and 120volt operation, should be an easy adaptation to
do the 120/240 series/parallel thing as well.
just an option
bob g
Bob & Bruce,
Thanks very much for those explanations. Most helpful.
In the meantime, I contacted the manufacturer of my welding machine.
Seems that may people are successful in welding with this machine when powered by a 15 amp wall outlet.
Although it's rated for much higher amperage, this unit can stick weld 1/8" to 1/4" material when using 3/32 rods as long as the stick amps is set to 80A.
I will give this a try first before doing any ST5 rewiring.
This will pull the max from one leg of my ST, but I can apply a bit of load to the other leg to balance things out.
If that does not work, I will pursue the ideas brought forth here.
Thanks again,
veggie
The ST-5 being rated at 5KW is 2500w per leg. At 120v, that would be 20A. I suspect it could handle quite a bit more than that for the short period of time that you are welding. It may groan and make ugly noises, but I suspect that it would work just fine. Although I haven't used my stick welder on the ST, I have used the 120v wire feed miller 130 without issues.
another option or two
there are countless web articles on building welders with microwave transformers, they appear to work quite well
there is also a website illustrating the use of a hd automotive alternator as a welding generator, it to appears to work well.
of the two, i would probably explore the use of an automotive alternator, because it operates as a 3phase low ripple dc
power source, so it should make a nice clean welder..
then of course there is looking at your local craiglist or welder supplier for a used portable welder, such as a miller, or lincoln
often times these can be bought very reasonably and are real welders capable of doing series work, much more so
than a 120v cracker/buzzbox welder. they also have built in generator capability which gives you a layer of redundancy.
i have seen good machines going for a couple hundred up to whatever you wanna spend, 500 should get you a good machine
that is ready to go to work.
just a thought fwiw
bob g