208v?? (1 Viewer)

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2badfjs

2badfjs

Joined
Jan 26, 2005
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my hobart 180 says 220v or 230 i don't remenber.
my shop has 208v, thats what the box says.

is this gonna be a big deal?
we have to run new power into the shop so mt question is....can my welder run off the 208v?

i searched the hobart forum and i'm an electrical idiot.

any help is appreciated.

jim
 
Hey Jim

It may run, but I can just about guarantee you that it won't be good for the welder. It is never healthy to run electric equipment on less voltage than it is designed to use. For example, it will likely affect the welder's duty-cycle.

Also, I believe 208V means it is 3-phase power, which is a whole 'nother ball of wax. Running a single-phase load could be problematic. Might want to have a sparky take a look at this one!
 
Check each leg to make sure.
But I dont think you want 208 I think its the type of transformer you have.
I believe the 208 is called the stinger leg.

Im sure somebody will correct me.



ken
 
Going out on an electrical limb here, you should be able to run the welder just fine at 208 but your (the welders performance) will not be at spec. You may not get the duty cycle listed on the machine.


If you have 208, and need 230 for your equipment to run at the "right" voltage I would suggest a buck/boost transformer to gain the few extra volts you need. It will get you right on 230 and should be good to go.
 
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ff347 said:
Going out on an electrical limb here, you should be able to run the welder just fine at 208 but your (the welders performance) will not be at spec. You may not get the duty cycle listed on the machine.


If you have 208, and need 230 for your equipment to run at the "right" voltage I would suggest a buck/boost transformer to gain the few extra volts you need. It will get you right on 230 and should be good to go.
Click to expand...

did i just talk to you on the hobart tech line?

they said i would probably have to turn the heat up but it still might not perform correctly.
and if the voltage dropped below the 208, the welder might not perform at all :frown:

whats a buck/booster transformer and is it something i can install myself?
 
Jim, I was just doing some searches on here...and saw your post..hahah...(I'm working with Jim on this to get it working).

208v is what you get when connecting any two hot wires from a 3-phase 208Y setup.

Any device that is basically a heater, which creates heat by dropping voltage across a resistance will be affected by the voltage...since dropping 208 volts does not make as much current flow as dropping 230 volts. If the device has some sort of switching supply then it won't matter because a switching supply can handle a wide range of incoming voltages because it can change it's duty cycle to create whatever internal voltage it wants. However, a welder is not one of those things. A welder is basically a transformer which has a ratio between incoming voltage and outgoing voltage. That ratio is fixed by taps in the transformer. As you turn your welder up, what you typically are doing is just increasing the voltage on the welding wire, i.e. selecting a different tap of the transformer which has a different ratio.

Now...all that told...my Lincoln Pro-Mig 175 (i.e. identical specs to the Hobart/Miller one) has a rating for running on 230v and a different rating for running off 208v. On 230v it'll draw up to 20amps and welds with a duty cycle of 30%...on 208v it'll draw up to 22amps with a duty cycle of 25%.

So, as long as you weren't totally maxing out your welder before, I don't envision any problems with this.

I'm looking up for some pics of the actual sine-wave to show why it's 208v and not 230v.

Here we go...

What you're looking at here is the voltage on each wire of a 3-phase circuit. What you're notice is their is 120-degrees of delay between each phase. This means that there is no point where one phase is peaking and another is bottoming out. If one was peaking and one was bottoming out, they would be 180-degrees apart...which is normal home wiring (mistakingly termed "single phase" often, even though it's not single, it's 2-phase). In a 3-phase setup the phases are closer to each other (120 degrees apart, versus 180 degrees) but that means the peaks and valleys don't line up...so you don't get quite as high of voltage.

Three_phase_voltages.png
 
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AC voltages don't always add up as we think they would when they are out of phase with each other. Two sources of 120 AC voltage connected in series with each voltage source 120 degrees out of phase will not add up to the same 240 volts as two 120 volt lines 180 degrees out of phase.

If your welder can run off of 120/208, then you would see a drop in duty cycle and an increase in your voltage setting.
208v 01.jpg
 
2badfjs said:
did i just talk to you on the hobart tech line?

they said i would probably have to turn the heat up but it still might not perform correctly.
and if the voltage dropped below the 208, the welder might not perform at all :frown:

whats a buck/booster transformer and is it something i can install myself?
Click to expand...

Basically, a buck/boost either shaves/adds voltage when put in line with whatever your need is. Some things can not stand to have any voltage other than the specified voltage, say 230,other items are much more forgiving. Your welder would do just fine from 208-240 just with different results, you will just get the best results at 230.

figuring your need
1. difference in voltage required, in your case 22 volts, either pick a 16volts or 24 volts.
2. multiply the voltage you chose by the amperage, that's your subtotal
3. multiply subtotal by 1.2 for a safety factor= your total VA need


And yes you can install it easily! If you need a little more specifics pm me and I will call our tech dept and I'll get you the exact Square D part number you need.

Now, fab me some 100 sliders! ;)

Scott
 
you need a Square D model# 750SV43F, how about them apples!

Scott
 
all i hear is Charlie Browns teacher talking here :doh:

mark, your waves are making me dizzy :eek:

let me know if i need to buy that thing mark ;)
 
mabrodis said:
Good work!

How much current can that boost converter take? I just found one on ebay, which states "Buck and Boost Transformer, Power Rating 0.75 Kilo Volt Amp, Secondary Voltage 12/24 Volts, Temperature Rise 115 degrees Celsius"

0.75 Kilo Volt Amp?? Not sure what that means.

http://cgi.ebay.com/NEW-SQUARE-D-BU...-750SV43F_W0QQitemZ170091055629QQcmdZViewItem
Click to expand...

Well,
I went on Hobarts website and looked and if I am correct that machine runs @ 20AMPS.
So with my handy instructional I figured

circuit amperage 20
needed "extra" 24volts
safety factor 1.2
20*24*1.2=576kva


Square D has a .50 and a .75 kva so you round up, atleast that is what I have been told in the past.

Scott
 
Tools R Us said:
Grab a meter and measure it? Mine reads 114V each leg and 224V across leg pairs.
Click to expand...

I did measure it...got 210 volts (some 2-phase outlets already setup for some window a/c units).

We're going to hook the welder up to the 208v first and just see how it runs.

What's very odd is my welder (Lincoln Pro-Mig 175), claims on 208v it'll draw up to a max of 22amps...but on 230v it'll draw a max of 20amps...that is very counter-intuitive. If that is actually true (and I'm not sure if I believe it) then somehow the welder has a method to up it's current usage based on the incoming voltage. If it really has that, that would be fairly cool, and unexpected, since that's more brains than I would expect. We'll see...
 
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unless you know what you are doing, DO NOT HOOK UP ANY SINGLE PHASE SYSTEM (110+/220+) TO THE 208 "STINGER" LEG.

Three phase wiring is a tad bit complex for the average joe. If your welder is set for single phase and can run on three phase -often something has to be switched
inside the unit and the wiring with the stinger hooked up just right or you will fry things.

110 (120) is built on one hot leg and one neutral and can be grounded.

220 (240) is built on two hot legs (out of phase to one another, but considered single phase) and a ground- sometimes a 4th neutral is used.

I've wired 3 phase correctly and also run a series of 110 outlets on it to blow up a scale and almost fry my hand drill. I will not explain as it's easier to teach in person . Hire a pro.
 
common non-industrial 3 phase is 2 110/120 volt legs and one 208 volt "wild "leg... thus the 3 phases........
 
I am an electrician and electricity is NOT a hobby. Hire a pro. And a 240v single phase wired welder will not work correctly on a 208v 3 phase system. It will give you poor performance and likely burn up your unit. Also there is no "wild leg" on a 208v system only 120v to ground and 208v phase to phase. Just think of a single phase 120/240v set up. The wild or stinger leg is on a Delta wired 3 phase 480/277v system (UNCOMMON) where you will find 277v to ground on one leg. Hope this clears some things up.
 
KNUCKLES said:
I am an electrician and electricity is NOT a hobby
Click to expand...

I agree completely, definetly need to know what you're doing, and do your research.

KNUCKLES said:
And a 240v single phase wired welder will not work correctly on a 208v 3 phase system. It will give you poor performance and likely burn up your unit.
Click to expand...

I agree if the welder is only designed for 230/240v operation, however, many of these welders (mine for example) state right on them they are for 208v or 230v. I agree that lower voltage should give less performance, but it certainly couldn't be bad for the welder if it's plainly stated you can run it at that voltage. Now that's for my welder, not Jim's...though his is identical specs, just from a different company...which ofcourse could mean totally different internal parts, but certainly not a cost issue, since I'm sure my Lincoln was cheaper than his Hobart. Interesting, just looked up the specs on the Hobart and Miller welders, neither appears (unless I had the wrong spec sheet) to say anything about running on 208v...but my Lincoln does...odd since normally all the 175/180 welders have exactly identical specs for everything...huh...

In anycase, we'll let you all know what we find out...

:cheers:
 
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