How To Wire A Welder? Electrical Wiring Tips

[Ripper]

Hi all

Got myself a 250A stick welder but having problems with supplying power to it off my garage electrical setup.

At present, i have routed power off the mains ahead of the home circuit to my garage and it's controlled via a 15amp breaker.

15amps is good enough to run the 2hp compressor and my powertools with ease but it trips when i hook up the welder and go beyond the first power setting.

My home supply at the moment is only single phase although the welder can run both single and three phase.

After going through the welder manual, it looks like it needs 40Amps to run at full power in single phase.

So i was thinking of getting an auxiliary line off the mains straight up and run it through a 50amp slow burning fuse and a 40amp breaker.

Just to be safe, thought of getting an independent ground connection to this circuit.

Is this the best way to do it?

Have heard of electrical interference from welders and one has to employ isolators but have no idea what those are and how they work etc.

Appreciate if any electrical experts can chime in on this with some tips

have attached a pic with my planned setup

[XBeat]

There are several facts to consider in this case

For a 250 A welding current the in put capacity is around 9.5 kW approximately. this means you may require approximately 41 A in 1 Phase or 14A in three phase. General domestic connection in 1Phsae is 30A. Since LECO/CEB is not giving multiple connections to a single consumer adresss you may require to upgrade your connection to 60A single phase or 30A three Phase.

If you upgrade for 60A Single phase it is more suitable to install a 63A adjustable MCCB than 40A Breaker and fuse combination. using a common earth is more reliable and safer than two seperate earths. You may require an RCCB 63A, 100mA in upstream for protection.

[Ripper]

There are several facts to consider in this case

For a 250 A welding current the in put capacity is around 9.5 kW approximately. this means you may require approximately 41 A in 1 Phase or 14A in three phase. General domestic connection in 1Phsae is 30A. Since LECO/CEB is not giving multiple connections to a single consumer adresss you may require to upgrade your connection to 60A single phase or 30A three Phase.

If you upgrade for 60A Single phase it is more suitable to install a 63A adjustable MCCB than 40A Breaker and fuse combination. using a common earth is more reliable and safer than two seperate earths. You may require an RCCB 63A, 100mA in upstream for protection.

thanks for the reply mate. sounds complicated.

Maybe i'll drop in at the welding joint near my house and see how that guys has his wiring done.

thanks again.

[Sylvi]

Hi all

Got myself a 250A stick welder but having problems with supplying power to it off my garage electrical setup.

At present, i have routed power off the mains ahead of the home circuit to my garage and it's controlled via a 15amp breaker.

15amps is good enough to run the 2hp compressor and my powertools with ease but it trips when i hook up the welder and go beyond the first power setting.

My home supply at the moment is only single phase although the welder can run both single and three phase.

After going through the welder manual, it looks like it needs 40Amps to run at full power in single phase.

So i was thinking of getting an auxiliary line off the mains straight up and run it through a 50amp slow burning fuse and a 40amp breaker.

Just to be safe, thought of getting an independent ground connection to this circuit.

Is this the best way to do it?

Have heard of electrical interference from welders and one has to employ isolators but have no idea what those are and how they work etc.

Appreciate if any electrical experts can chime in on this with some tips

have attached a pic with my planned setup

'Ripper',

XBeat has given the best advise for your problem I too would have given the same so follow his advice.

Only thing what is the tariff you pay now is it domestic. How many units you consume for a month. If it is domestic you are going to do commercial work better to convert your domestic to commercial connection

I use average of 35 units to 45 units a day. Pay commercial tariff for a day costing me about under Rupees 1000.00. Only for my house.

I have in all 9 water pumps to serve different requirements.

I have used Power Factor correction Capacitor bank to the main supply which I have for my entire building. A 100 ampere copper underground cable supply underground cable only Building in this area has that.

Now days all supplies are aluminum cables. My maximum draw of current in working hours are 70 amperes on each phase. Protected with a 100 ampere Main MCCB with a bus bar arrangement. There are three meters every supply has a isolator. Meters reading the units consumed by different connections of the building totaling out to over 2500 units for a month and entire commercial area is fitted with A/C units and very good lighting arrangement for power saving

Electronic meter which notes the voltage amperage and cycles of the supply always on.

Sylvi Wijesinghe.

There are several facts to consider in this case

For a 250 A welding current the in put capacity is around 9.5 kW approximately. this means you may require approximately 41 A in 1 Phase or 14A in three phase. General domestic connection in 1Phsae is 30A. Since LECO/CEB is not giving multiple connections to a single consumer address you may require to upgrade your connection to 60A single phase or 30A three Phase.

If you upgrade for 60A Single phase it is more suitable to install a 63A adjustable MCCB than 40A Breaker and fuse combination. using a common earth is more reliable and safer than two separate earths. You may require an RCCB 63A, 100mA in upstream for protection

[Ripper]

'Ripper',

XBeat has given the best advise for your problem I too would have given the same so follow his advice.

Only thing what is the tariff you pay now is it domestic. How many units you consume for a month. If it is domestic you are going to do commercial work better to convert your domestic to commercial connection

I use average of 35 units to 45 units a day. Pay commercial tariff for a day costing me about under Rupees 1000.00. Only for my house.

I have in all 9 water pumps to serve different requirements.

I have used Power Factor correction Capacitor bank to the main supply which I have for my entire building. A 100 ampere copper underground cable supply underground cable only Building in this area has that.

Now days all supplies are aluminum cables. My maximum draw of current in working hours are 70 amperes on each phase. Protected with a 100 ampere Main MCCB with a bus bar arrangement. There are three meters every supply has a isolator. Meters reading the units consumed by different connections of the building totaling out to over 2500 units for a month and entire commercial area is fitted with A/C units and very good lighting arrangement for power saving

Electronic meter which notes the voltage amperage and cycles of the supply always on.

Sylvi Wijesinghe.

There are several facts to consider in this case

For a 250 A welding current the in put capacity is around 9.5 kW approximately. this means you may require approximately 41 A in 1 Phase or 14A in three phase. General domestic connection in 1Phsae is 30A. Since LECO/CEB is not giving multiple connections to a single consumer address you may require to upgrade your connection to 60A single phase or 30A three Phase.

If you upgrade for 60A Single phase it is more suitable to install a 63A adjustable MCCB than 40A Breaker and fuse combination. using a common earth is more reliable and safer than two separate earths. You may require an RCCB 63A, 100mA in upstream for protection

Thanks Sylvi

I dont plan on doing heavy or constant work with this. It's a small portable unit i bought for my DIY projects at home.

I've had professional welder chaps coming home to do weld jobs before and they have used portable units without a hitch. They usually take power straight off the main line so none of the household breakers or fuses are involved.

I was just wondering if those guys could run their machines, chances are...i too can run mine with the correct safety features without upgrading lines etc.

There is a weld shop close to my home and that chap too operates out of his garage sorta thing. will have a chat with the bloke and see how he has done it.

[The Don]

Ripper, while we're on the subject, do you know of any welders who do spot welding on automotive body repairs? I'm thinking about replacing a panel and I assume it was originally spot welded and the advice seems to be to drill through the spot welds, take the existing panel out, put the new panel in and spot weld it back. Completely new subject to me so I wondered if you had any perspective.

Also did you get an arc or a mig welder?

[Ripper]

Ripper, while we're on the subject, do you know of any welders who do spot welding on automotive body repairs? I'm thinking about replacing a panel and I assume it was originally spot welded and the advice seems to be to drill through the spot welds, take the existing panel out, put the new panel in and spot weld it back. Completely new subject to me so I wondered if you had any perspective.

Also did you get an arc or a mig welder?

Got a AC stick welder machang. regular arc.

Wanted a mig but the costs were little beyond me at the moment. 250A mig unit alone is north of 150,000. Then comes the cost for the argon cylinder etc so a mig would have to wait

I just needed something to start off with so this should work for the moment. The Mig will come if i master the arc

As for a spot welder.

CRC in seeduwa (former formulaworld of SLIC) has a couple of spot welders, Migs, tigs etc. Also they are pretty good at repairs. They do understand crumple zones etc so welding things solid as some wayside buggers would do. At least that's how it was when it was under SLIC.

Worth a shot checking with them to see if they can sort out at least that part should they prove to be cost prohibitive for the whole project.

Edited October 3, 2012 by Ripper

[The Don]

Got a AC stick welder machang. regular arc.

Wanted a mig but the costs were little beyond me at the moment. 250A mig unit alone is north of 150,000. Then comes the cost for the argon cylinder etc so a mig would have to wait

I just needed something to start off with so this should work for the moment. The Mig will come if i master the arc

As for a spot welder.

CRC in seeduwa (former formulaworld of SLIC) has a couple of spot welders, Migs, tigs etc. Also they are pretty good at repairs. They do understand crumple zones etc so welding things solid as some wayside buggers would do. At least that's how it was when it was under SLIC.

Worth a shot checking with them to see if they can sort out at least that part should they prove to be cost prohibitive for the whole project.

Thanks for the info! I shall look into it the next time I'm down.

I also noticed mig welders without gas on ebay. Now I remember my boss had a mig welder but he certainly didn't have a cylinder attached to it. Is this a different type of welder?

[Scooter]

Stick welders aren't too useful on car body repairs. (Unless you are welding up a heavy chassis or a tow bar or something like that). Trick on thin metal is small rod+minimum amps+ a backing plate (aluminium is best) to suck away the excess heat+short weld runs. So you might want to just experiment for a while on the low setting that doesn't trip your circuit breakers. Frankly, I just don't suggest the stick units for cars, mig is the way to go.

There is one gadget around that I use on the Arc that makes it more useful for thin metal. Try a search on ebay for "car body stick welder" and you'll find little units that fit on the end of your welding cable and to which you then attach your rod. The unit sort of vibrates and makes/breaks the arc and reduces blow through. They're about $70 or $80. They help with thin car body metal but I still prefer to use a mig. If consumable costs are an issue, there are the gas-less migs...again, they're "OK".

One thing arc welders do do good is spot welding. You can get a cheap "spot welding gun" - see ebay - which is fitted to the end of the welding cable.They work real well.

Other thing that has got cheap recently are automatic darkening helmets. Get one. It makes life a doodle when you are striking an arc.

Welcome to the world or arc welding, Ripper, it's all blow throughs, itchy eyes and holes in the jeans from now on!

[Ripper]

Thanks for the info! I shall look into it the next time I'm down.

I also noticed mig welders without gas on ebay. Now I remember my boss had a mig welder but he certainly didn't have a cylinder attached to it. Is this a different type of welder?

MIG have to have a shielding gas machang cos the moment the metal weld rod becomes melted upon arcing, it needs to be shielded from atmospheric oxygen. Or else the super heated metal will react with O2 and screw up the strength of the weld. Also...MIG stands for Metal Inert Gas... "Inert" is where argon gas gets into the picture There are some machines that can use CO2 instead of argon though.

This "shielding" issue is why even typical stick welding rods have a flux core around it. As this core burns, it emits gases to shield the weld pool from messing with atmospheric gases

MIG welders are actually just like stick welders in terms of the current part of things but have a wire feed roll instead of welding rods. And the wire is uncoated.

So maybe when you saw that particular mig plant, it would've appeared to be without a gas cylinder. But i doubt it can work without the gas.

would like to take a look at that ebay link though

I've read extensively online about welding bits maybe the info i got was outdated.

[Ripper]

Stick welders aren't too useful on car body repairs. (Unless you are welding up a heavy chassis or a tow bar or something like that). Trick on thin metal is small rod+minimum amps+ a backing plate (aluminium is best) to suck away the excess heat+short weld runs. So you might want to just experiment for a while on the low setting that doesn't trip your circuit breakers. Frankly, I just don't suggest the stick units for cars, mig is the way to go.

There is one gadget around that I use on the Arc that makes it more useful for thin metal. Try a search on ebay for "car body stick welder" and you'll find little units that fit on the end of your welding cable and to which you then attach your rod. The unit sort of vibrates and makes/breaks the arc and reduces blow through. They're about $70 or $80. They help with thin car body metal but I still prefer to use a mig. If consumable costs are an issue, there are the gas-less migs...again, they're "OK".

One thing arc welders do do good is spot welding. You can get a cheap "spot welding gun" - see ebay - which is fitted to the end of the welding cable.They work real well.

Other thing that has got cheap recently are automatic darkening helmets. Get one. It makes life a doodle when you are striking an arc.

Welcome to the world or arc welding, Ripper, it's all blow throughs, itchy eyes and holes in the jeans from now on!

ha ha ha

thanks for the info machang!

I didn't want to bust a lotta money on the first go. hence the cheaper stick unit.

If i get it right...i will buy a MIG for sure. Like you say...it's the best for thinner material and supposedly far easier to master than the stick.

And for the tripping thing...i can get the plant going fine on 1st power setting. the moment i go beyond that, before even getting a spark the trip kicks in.

Also it seems to be difficult to keep the arc going in low setting. Mind you i'm a complete noob for welding

thought it was cheap enough to start off with a stick welder so thought why not

btw...dropped you a PM

Edited October 3, 2012 by Ripper

[Scooter]

Try a couple of 3/32" / 2.4mm rods with the low amps. The 6013 range are pretty good for all-round welding. Make sure the rods are new and dry; that's really important. Good way to start is to get a nice chunk of mild steel and just play away striking an arc and making puddles. Then try welding a few bits and pieces onto the plate and practise removing the slag.

And I'm not knocking arc welders at all, I've seen some people who really can weld thinnish metal with the units, it's just that they have had so much experience in using them in their jobs.

BOC have a well illustrated introduction to arc welding guide here

http://www.bocworldofwelding.com.au/media/pdf/file/library/WOWLibrary-Fundamentals%20MMA%20welding.pdf

Enjoy....

[The Don]

MIG have to have a shielding gas machang cos the moment the metal weld rod becomes melted upon arcing, it needs to be shielded from atmospheric oxygen. Or else the super heated metal will react with O2 and screw up the strength of the weld. Also...MIG stands for Metal Inert Gas... "Inert" is where argon gas gets into the picture There are some machines that can use CO2 instead of argon though.

This "shielding" issue is why even typical stick welding rods have a flux core around it. As this core burns, it emits gases to shield the weld pool from messing with atmospheric gases

MIG welders are actually just like stick welders in terms of the current part of things but have a wire feed roll instead of welding rods. And the wire is uncoated.

So maybe when you saw that particular mig plant, it would've appeared to be without a gas cylinder. But i doubt it can work without the gas.

would like to take a look at that ebay link though

I've read extensively online about welding bits maybe the info i got was outdated.

Thanks for the explanation and that is what I've read as well. But as Scooter alluded to there is this so called gas less Mig welder...

http://www.ebay.co.uk/sch/i.html?_trksid=p5197.m570.l1311&_nkw=mig+welder&_sacat=0&_from=R40

Now you see both the standard and the so called gasless in the lisings. I'm curious as to what these gas less Mig welders are...

[Scooter]

Full migs run gas to the torch tip to shield the weld from atmosphere. Gas-less migs have a flux thread in the welding wire that melts and produces a gas that also works to shield the weld from the atmosphere. Course, they get you coming and going, you're either paying for a more complex machine+gas bottle or shelling out for more expensive wire spools! The weld off the gas-less migs is "OK" but they're not as good as a "proper"mig.

[terrabytetango]

We have a 400A stick welder which we use out of the garage socket. We normally use it between 250 and 300, but once I cranked it to 11 400 and blew the transformer. I believe there's no need to upgrade your wiring, ours works fine out of a 15A plug. The calculations in post #2 are off since the voltage coming out of the unit is ~50v-80v, not 220v-230v. I think you might have an earth leak with your independent earth setup.

[Ripper]

We have a 400A stick welder which we use out of the garage socket. We normally use it between 250 and 300, but once I cranked it to 11 400 and blew the transformer. I believe there's no need to upgrade your wiring, ours works fine out of a 15A plug. The calculations in post #2 are off since the voltage coming out of the unit is ~50v-80v, not 220v-230v. I think you might have an earth leak with your independent earth setup.

yep...i too felt welding current is no indication of operating current cos it's a transformer thing in there. But wasn't really sure of it.

15A wont cut it for me for some reason machang cos the breaker keeps on tripping. even in low setting. However, i didn't have the machine grounded at the time of testing.

The stupid power plug doesn't have a proper ground connector although the manual says you gotta ground the thing. So i'd have to hook up a ground wire to the casing and jerry rig something up.

you reckon after grounding it properly it should work off 15A?

I bought it in panchi and they tested in front of me without a ground wire. And it worked without tripping anything

Will have a chat with my welding shop dude too.... that guy runs two units. one oil cooled and the smaller air cooled one just like what i got.

Just another stupid Q. If one were to touch the positive line coming off the welder, will that give a thadi shock?

prefer to work without gloves but that's risking touching the electrode at some point for sure...

[terrabytetango]

Thadi shock only if you earth yourself somehow. You will however feel the current flow through you, but you should be able to handle it (I can't, I'm shit scared of electrocution). And yeah, it should run fine from the 15A plug. The other thing might be that the ELCB you're using might be a little iffy. We had to replace one in our house because it became too sensitive and would trip at the slightest provocation.

[Ripper]

Thadi shock only if you earth yourself somehow. You will however feel the current flow through you, but you should be able to handle it (I can't, I'm shit scared of electrocution). And yeah, it should run fine from the 15A plug. The other thing might be that the ELCB you're using might be a little iffy. We had to replace one in our house because it became too sensitive and would trip at the slightest provocation.

i got a dedicated unit just for the garage power supply machang. that sucker can handle upto 15 and trips beyond that.

The main homen breaker doesn't get involved in this cos the garage supply is direct to the mains ahead of the home system

will try the earth thing over the weekend and see if that work...

[terrabytetango]

i got a dedicated unit just for the garage power supply machang. that sucker can handle upto 15 and trips beyond that.

The main homen breaker doesn't get involved in this cos the garage supply is direct to the mains ahead of the home system

will try the earth thing over the weekend and see if that work...

We use a second phase for the garage and other heavy duty electrics in the house, both phases have a main breaker each, and then hook up to a big ass 30A 3 phase breaker. I'm not sure what amperage breaker is hooked up to the garage outlet, I think it might be a 20A. I'll update this post once I confirm it this evening.

Update: Garage outlet is on a 20A breaker while the main breaker on the panel is a 40A.

Edited October 4, 2012 by terrabytetango

[XBeat]

If the Welding transformer is of Oil Bath Type the current drawn by it is low. Generally at full load single phase it is around 30A for a 250A transformer

.

Irrespective of the type whether it is 'Oil bath" or "air cooled" you should be able to plug it on No Load, The general no load current (i.e when not welding) is around 3~ 6 Ampere.

If you set the welding current to about 120A then it can be operated from a 15A socket outlet.

It is better to tap the welder supply before the trip switch of the house to avoid

01. Unnecessary Tripping due to earth leakage

02. Overloading of the cables inside conduites

It is not necessary to connect the frame earth of the welder to start welding. The eath is provided there for protection from the ground faults.

If the welder keeps on tripping even on no load then it must have a short circuit fault inside ( Can be a loosen phase lead touching the body or neutral; or the worst case the transformer winding has a short circuit)

You will get a "thadi shock" only if your body become a part of conductive path between +ve and -ve terminals to create a close circuit between the two.

Edited October 5, 2012 by XBeat

[Ripper]

thanks for the info guys. took the welder to the nearby weld shop and got the guy to power it up and weld through all the ranges and it worked like a charm. no tripping. nothing.

tried it at home a while back and for some reason, when you power it in 3rd power setting..no tripping. Go down first setting and it trips.

I welded a bit on 3rd power setting but at the slightest hint of "sticking" the breaker trips. Mind you i didn't get any stickups, just that "almost stickup" point the breaker trips.

I'm assuming the breaker i have hooked is hyper sensitive. possibly female

although it's 15A, at the slightest bloody feel of a stick up it trips...

is there a sensitivity setting other than just the amperage for breakers?

Spoke to the lady at the hardware shop but she was utterly clueless

[terrabytetango]

If the Welding transformer is of Oil Bath Type the current drawn by it is low. Generally at full load single phase it is around 30A for a 250A transformer

.

Irrespective of the type whether it is 'Oil bath" or "air cooled" you should be able to plug it on No Load, The general no load current (i.e when not welding) is around 3~ 6 Ampere.

If you set the welding current to about 120A then it can be operated from a 15A socket outlet.

It is better to tap the welder supply before the trip switch of the house to avoid

01. Unnecessary Tripping due to earth leakage

02. Overloading of the cables inside conduites

It is not necessary to connect the frame earth of the welder to start welding. The eath is provided there for protection from the ground faults.

If the welder keeps on tripping even on no load then it must have a short circuit fault inside ( Can be a loosen phase lead touching the body or neutral; or the worst case the transformer winding has a short circuit)

You will get a "thadi shock" only if your body become a part of conductive path between +ve and -ve terminals to create a close circuit between the two.

have you ever operated an electric welding plant?? kindly stop spewing out crap you find on google.

[terrabytetango]

thanks for the info guys. took the welder to the nearby weld shop and got the guy to power it up and weld through all the ranges and it worked like a charm. no tripping. nothing.

tried it at home a while back and for some reason, when you power it in 3rd power setting..no tripping. Go down first setting and it trips.

I welded a bit on 3rd power setting but at the slightest hint of "sticking" the breaker trips. Mind you i didn't get any stickups, just that "almost stickup" point the breaker trips.

I'm assuming the breaker i have hooked is hyper sensitive. possibly female

although it's 15A, at the slightest bloody feel of a stick up it trips...

is there a sensitivity setting other than just the amperage for breakers?

Spoke to the lady at the hardware shop but she was utterly clueless

No adjustable sensitivity, the cheaper ones are more sensitive because rather than cause fires the manufacturers err on the safe side and cause them to trip earlier. The mindset is that very rarely would these ever be pushed to their stated operational limit. We use Federal Electric breakers in all the sub panels, and the main 3 phase breaker is a Merlin Gerin.

I say get yourself a proven, reliable brand and save yourself the headache of sorting out avoidable electrical issues.

[Scooter]

Ripper, haven't ever bought a circuit breaker on the SL market, but as I understand it there is more than the amp rating to the breakers. The breakers are also rated on a scale B thru D referring to level of load current which causes a trip . A "D" rating is recommended for arc welding. The "D" rated breaker trips at a much higher load than a "B" and copes better with the rush current you get from the welding transformer coming on line. I don't know what range of breakers is available to you in SL, but it could be worth looking at your present unit to see if it has a letter attached to its rating and maybe see if you can buy a "D" rated one. You might want to check all this with your electrician to make sure a "D" is OK on your wiring. Hope this helps you get back on line so that the merry buzz of the box can be heard echoing from your garage as practise you welding :-)

[Ripper]

Thanks TBT and Scooter,

I didn't think of the breaker thing that seriously so bought one off a closeby hardware joint. the brand is orange. rated 15A and seems like class "C"...it says "C10"

Just read up on it and looks like this is the cause for my tripping issue

Will see if i can get a type D and see...

Thanks again boys for the info