415V 1ph Welder....

[Shovelhands]

as above, I have an old welder I’d like to get going and use, if I can’t then there’s no point in it taking up space any longer!

We’ve dragged it out and dusted it off this afternoon, I knew it was 415V, but it’s wired with up with what looks like a length of 6mm single phase cable, on the front it says 415V 1ph, so......I am assuming that the only way I can achieve this is to connect one wire, the brown live wire to L1, and the other wire, the blue which would be neutral on single phase, to L2.
But surely this is then dual phase or 2 phase?
How else can 415v 1hp be achieved?

Anyone have any experience of this kind of thing?

Any ideas are much appreciated

 

[defender]

Assuming this is a stick welder then it should be ok to connect up 2 phases to give you 415 volts , no separate neutral needed as each line is neutral for the other , connect the earth wire as normal
a lot of old welders could be connected either 240,415 0r 480 volts depending on the tapping point of the winding

 

[Shovelhands]

Yes, sorry, should have said it’s a stick welder.

 

[defender]

what it means by single phase in this case is that it uses 2 lines of power only -line 1 - line 2 =415 volts
in a 3 phase set up you use 3 connections at 415 volts or
L1 - L2 L2 - L3 and L3- L1

 

[Shovelhands]

what it means by single phase in this case is that it uses 2 lines of power only -line 1 - line 2 =415 volts
in a 3 phase set up you use 3 connections at 415 volts or
L1 - L2 L2 - L3 and L3- L1

That’s what I thought but when I’ve seen this before, admittedly not very often, it’s said 2ph or dual phase, not 1ph.

I will get a plug for it Monday and wire it up, see if she goes

 

[Zebbedee]

Might be and idea to lift the cover where cable goes into welder and check what way it is configured eg what voltage? As defender said most could be used on any voltage by changing the wire tapping,it is usually labelled under the cover

 

[Shovelhands]

Might be and idea to lift the cover where cable goes into welder and check what way it is configured eg what voltage? As defender said most could be used on any voltage by changing the wire tapping,it is usually labelled under the cover

I’ve got the cover off it, there is simply a choc block that the cable goes into, no way of altering the configuration. And it doesn’t say anything about different voltages or phases anywhere.

Admittedly the choc block may not be original?, I don’t know, plug it in and find out I suppose

 

[aidan]

Sounds like a v old and v powerful machine

 

[Netherfield]

Never seen an old stick welder that uses all three phases, isn't there any makers name on the machine.


Picture paints a thousand words.

 

[Courier]

If it's using both sides from a single phase supply then there could be + 240 v and - 240 v giving you a PD of 480 volts as in single (split phase) 480 volt motors.

 

[Courier]

Assuming this is a stick welder then it should be ok to connect up 2 phases to give you 415 volts , no separate neutral needed as each line is neutral for the other , connect the earth wire as normal
a lot of old welders could be connected either 240,415 0r 480 volts depending on the tapping point of the winding

And double up on the Earth for safety - Who knows what the state of the insulation within will be like - Preferably connect it through a high capacity breaker.

 

[Pheasant Surprise]

If it's using both sides from a single phase supply then there could be + 240 v and - 240 v giving you a PD of 480 volts as in single (split phase) 480 volt motors.

I was thinking about this when the thread was brought up. Seeing as its labelled 415v/single phase, I don't believe the welder was designed for an old fashioned countryside special split-phase 240/480v supply i.e. from the supply company two actives 180 degrees out of phase gives you 480 V.....

If it was hooked up to 2 legs (L1 and L2) of a three-phase supply then its only ever going to get max 415 volts across L1 and L2 say, as the phases are 120 degrees apart.

If it was 'proper' oldee-worldee split phase supply then it would be nominal 480V (and would also pull less current than it would out of two legs of a three phase supply).

Hope that makes sense.

 

[Shovelhands]

Sounds like a v old and v powerful machine

No idea how old it is, I’m guessing around 30yrs + ?

Never seen an old stick welder that uses all three phases, isn't there any makers name on the machine.


Picture paints a thousand words.

I should have added a pic or two....I hadn’t thought much about it when I was looking at it last night, and then thought I’d ask on here once I was home. Unfortunately I have just returned from the yard, and I’d not looked in here before I left, so a pic will have to wait until tomorrow!

It’s an air cooled Oxford, 350amp iirc, A/C & D/C Arc welder

I was thinking about this when the thread was brought up. Seeing as its labelled 415v/single phase, I don't believe the welder was designed for an old fashioned countryside special split-phase 240/480v supply i.e. from the supply company two actives 180 degrees out of phase gives you 480 V.....

If it was hooked up to 2 legs (L1 and L2) of a three-phase supply then its only ever going to get max 415 volts across L1 and L2 say, as the phases are 120 degrees apart.

If it was 'proper' oldee-worldee split phase supply then it would be nominal 480V (and would also pull less current than it would out of two legs of a three phase supply).

Hope that makes sense.

I’m a bit lost with the first bit, but sort of grasp it....I’m sure it doesn’t say 480V, so would rule out split phase?

Iirc it says 380V-415V

I may be clutching at straws a bit, but I think I have found a plug, which iirc we nicked off it for something else, not realising that it was actually not the plug we needed, so it was left with the welder but not reconnected, it has L3 and the Neutral done up tight, like it hadn’t had anything in those terminals, and L1, L2 & the earth terminals were loose......this was all a long time ago, but the forensic evidence would suggest that this was the way it was wired up?.....

I shall pick up a plug tomorrow and hopefully find out in the next day or two weather it’s a goer

Thanks for everyone’s thoughts and input

 

[TheTallGuy]

If you still have the cover off (if not then take it off) and make sure that it is as clean as practical & inspect the wiring for fatigue & signs of degradation given its age.

Being single phase 415 will simply mean as you've correctly assumed that it should be wired between two phases. I could enter into a lengthy discourse about the terminology, but it would only serve to muddy the waters - even I have to think about it at times & I spent 20 years in engineering!

 

[defender]

I was thinking about this when the thread was brought up. Seeing as its labelled 415v/single phase, I don't believe the welder was designed for an old fashioned countryside special split-phase 240/480v supply i.e. from the supply company two actives 180 degrees out of phase gives you 480 V.....

If it was hooked up to 2 legs (L1 and L2) of a three-phase supply then its only ever going to get max 415 volts across L1 and L2 say, as the phases are 120 degrees apart.

If it was 'proper' oldee-worldee split phase supply then it would be nominal 480V (and would also pull less current than it would out of two legs of a three phase supply).

Hope that makes sense.

As far as I am aware the only difference between the 415 and 480 volt or even 240 volt welder is the length of the winding or the tapping point of the winding
it wasn`t unusual for the old welders you mention to have ability to run on
480 volts or 415 and even have a tapping for 240 volts
If you see old welders like that not working they are worth trying on a different voltage as sometimes it is only a bit of the winding that goes faulty . If I remember correctly you can come down the voltage but not go up

 

[Shovelhands]

If you still have the cover off (if not then take it off) and make sure that it is as clean as practical & inspect the wiring for fatigue & signs of degradation given its age.

Being single phase 415 will simply mean as you've correctly assumed that it should be wired between two phases. I could enter into a lengthy discourse about the terminology, but it would only serve to muddy the waters - even I have to think about it at times & I spent 20 years in engineering!

Thanks @TheTallGuy

Cover is off, we’ve blown the dust out of it! There’s a bit of wire, that needs replacing, only a short bit. But mostly it looks to be as it should be, it’s very basic and a robust simple machine. There’s an insulator around one of the output sockets that needs replacing, but I will see if it works first before I go trying to get parts for it.

 

[Pheasant Surprise]

As far as I am aware the only difference between the 415 and 480 volt or even 240 volt welder is the length of the winding or the tapping point of the winding
it wasn`t unusual for the old welders you mention to have ability to run on
480 volts or 415 and even have a tapping for 240 volts
If you see old welders like that not working they are worth trying on a different voltage as sometimes it is only a bit of the winding that goes faulty . If I remember correctly you can come down the voltage but not go up

Yes there is no way of getting 480V out of a standard three-phase supply. If the welder has only one set of taps and its labelled as 415V single phase then you're absolutely good to go to wire in L1 and L2 (or L2 and L3, or L3 and L1) from the 3-phase supply.

My post was on about the old split-phase supply which would have been actual 480V line to line voltage. No doubt some welders would have been set up for that - as it was pretty popular way of saving money on copper in the network post war, especially to farms etc in rural areas - as well as bog standard 240V single phase, albeit at a lower overall power output for the welder.

 

[Shovelhands]

Here she is, in all her glory....
I had a bit of a re-jig on the power cable, whoever fitted it previously was taking the pi$$! And the choc block is definitely not original. With that bit sorted, I stuck a new plug on it, connected to L1 & L2 as discussed

she’s had a life....but will hopefully do me a turn or two

plugged her in, fired the genny up......and hey presto, she choooches...well the light came on at least, fan runs, so I plugged some leads in to it and burnt a few rods. Both A/C & D/C work fine, jury is still out on what was best on the 7016 rods I’m trying to run, A/C or D/C?, but all I know is my old arc welder, which has done me well, and still goes, would not keep them ‘lit’ for some reason? But this old girl did. I didn’t play much, as I wasn’t appropriately dressed for welding! So we will see in the morning if it keeps going.
That 50V outlet needs a new insulator, but apart from that, it seems in ok order

 

[Shovelhands]

Well I’ve burnt a few rods with it, not the prettiest, but I’m new to these 7016 rods, that’s no excuse though, real reason is I’m only an amateur, so it’s not to bad.
On the plus side, the old Oxford hasn’t missed a beat

 

[Netherfield]

Glad to see it working, now have a check on your electric supply and see which phase is most used for the single phase items,then try use the other two phases for your welder.

Our supply being single phase originally,meant that a lot of load was on one cable going out of the power shed, once three phase was installed it became hard to balance the usage across all three phases, so the big welder was always used on the two least loaded phases.