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Primary power requirements for WeldAll units



SpyGuy
02-15-2010, 09:51 PM
I am interested in the WeldAll line of products, particularly the 160PI or 200PI. For primary power, do these WeldAll units use 2-wire 230VAC power (2 hots + ground) or 3-wire 230VAC power (2 hots + neutral + ground)?

jbman45
02-16-2010, 06:54 AM
As I recall they are all 3 wire hookups, i.e. two hots and ground. The 4 wire stuff came up due to some code changes on house wiring but neutral and ground are tied together back at the panel so only worry is if you have other stuff besides your welder hooked into the circuit which would be running 110 service, then the neutral would be carrying current. (Like sometimes a dryer or elec stove will have 220 and 110 parts). If you're putting in new service 3 wire 220 is fine as long as you don't want to pull 110 off it for another branch circuit, then you should probably go to 4 wire; and then if you get a 4 wire unit someday you can always merge neutral and ground at that plug.

KHK
02-16-2010, 08:22 AM
Two Hots and a Ground is requited. There is a ground lug on the rear of the machine, it is used if you get HF noise.

SpyGuy
02-16-2010, 01:18 PM
First, let me clarify: when I say "2-wire" or "3-wire", I'm talking about current carrying conductors. Thus a typical "house" 115VAC branch circuit is 2-wire: 1 hot + 1 neutral + ground. A typical 230VAC branch circuit is also 2-wire: 2 hots + ground (no neutral). "Modern" branch circuits for electric clothes dryers are 3-wire (2 hots + neutral + ground) because the dryer requires 230VAC (hot-to-hot) for the heating elements, but needs 115VAC (hot-to-neutral) for the motor and controls.

Always remember that the neutral is a CURRENT CARRYING CONDUCTOR and should NEVER be tied to ground at any point beyond the service equipment panel (usually, this is where the meter is located)! If you tie the neutral to ground beyond the service equipment panel, then you can get current flowing on your ground which can be a LETHAL situation.

So my questions is: do any of the WeldAll units require a neutral (so they can pull 115VAC off the primary in addition to 230VAC)?

I suspect they only require "2-wire" service (2 hots + ground), but I want to be sure before wiring my shop.

Gadget
02-16-2010, 02:30 PM
they only need two hots and ground.

KHK
02-16-2010, 03:02 PM
Two Hots and a (Ground) is requited. There is a ground lug on the rear of the machine, it is used if you get HF noise.

There are three wires on the line cord from the welder. Black, white and green or green black stripe. The black and white are the power input wires for 240vac. The green is the ground, it is actualy connected to the welders chassie. The reasion that I encluded the quote is that I changed the word neutral to ground. Sorry!

SpyGuy
02-16-2010, 03:33 PM
Two Hots and a neutrial(Ground) is requited. There is a ground lug on the rear of the machine, it is used if you get HF noise.

You already corrected yourself, but your original post may still be confusing to some as you put "neutrial(Ground)" together. Just to be clear, neutral is NOT the same as ground, even though they are tied together at the service entrance.

A neutral conductor is a current carrying conductor: the exact same amount of current that is flowing through your 115VAC hot is also flowing though your neutral (excepting multiwire branch circuits, but that's beyond the level of this discussion). In fact that is how a GFCI works: it compares the current flowing through the hot and neutral lines. If the current is balanced ("out" = "in") then the load is safe. But if not balanced, that means that current is leaking to ground somewhere (and maybe NOT to the ground terminal in the GFCI). For example, it could be leaking through your body and into the bathtub drain pipe. So if the GFCI senses this imbalance between hot and neutral (even if there is NO current entering the GFCI's ground terminal), then the GFCI will almost instantly open and hopefully save your life.

A ground wire (the correct name is: "Equipment Grounding Conductor" or "EGC") should never carry current except in a ground fault situation (at which point it should cause the circuit breaker on the faulted branch circuit to immediately trip).

SpyGuy
02-16-2010, 11:21 PM
Today I called Longevity and confirmed that the WeldAll machines are all 2-wire w/ ground (2 hots + ground); no neutral required.

KHK
02-17-2010, 09:03 AM
Make sure that your groung wire is the same size as the supply voltage wires and goes all the way back to the house's ground.

SpyGuy
02-17-2010, 01:12 PM
Make sure that your groung wire is the same size as the supply voltage wires

Sorry Keith, but that's not entirely correct. The NEC only requires the Equipment Grounding Conductor (EGC) be minimally sized according to the following chart:

http://i748.photobucket.com/albums/xx128/SpyGuy10/NEC/T250122.png

As you can see, once you get beyond 30A, then the EGC is no longer sized 1-to-1 with the circuit conductors (hot wires). Sure, you can use larger wire for your EGC, but you are not required to do so.

(But note that if you increase the size of your "hots" (e.g., to compensate for voltage drop), then you must proportionally increase the size of your EGC.)

KHK
02-17-2010, 02:47 PM
Sorry SpyGuy, but the chart you show is for the MINUM wire size.

SpyGuy
02-17-2010, 03:07 PM
Sorry SpyGuy, but the chart you show is for the MINUM wire size.

That is correct. It means your EGC must be no smaller than the minimum sizes listed in that table to meet NEC requirements. Unless you are upsizing your current-carrrying conductors for voltage drop (long wiring runs) or temperature issues, there is no need to go larger than the NEC minimum requirements.

For example, if I were installing a 40A branch circuit, I would use AWG8 wire for my current-carrying conductors, and AWG10 wire for my EGC.

As I said in my last post: "Sure, you can use larger wire for your EGC, but you are not required to do so."

KHK
02-17-2010, 04:55 PM
So cut the BS and use the same size wire.

SpyGuy
02-18-2010, 05:37 AM
So cut the BS and use the same size wire.

Lol... well you might think the NEC is "BS", but I don't. And I have better things to do with my money than waste it on unnecessary copper and conduit (bigger wire means bigger conduit).

Btw, next time you're in an electrical supply shop (or your local home improvement store), take a look at 8/2 or 8/3 Romex cable. You'll see it's made with a 10AWG ground wire.

McAz
02-26-2011, 01:28 AM
So I just got a 160pi.. no tank yet so NO welding.. My WISE Dad is an Engineer, and a safty nut. I wired my garage with 6/3 Romex wire (3 shielded, 1 bare), probably overkill, but 25 feet at $3.08 a foot for wire alone I don't want to do it again for a bigger machine later. I ran my 2 hots and a ground, and volt metered it.. Machine fires right up.

My question is Pop says to use the Extra wire in the Romex to create ANOTHER GROUND. Run that from the House power box ground bar, to the outlet Box, and tie that directly to my 3x5 metal welding table to keep my Noob butt from blowing up. Is this necessary??
He also has concerns because here in Az it is HOT, and even though I KNOW I shouldn't, I tend to weld, cut and grind in MY garage in short sleeve shirts, shorts and sometimes even flip flops, and in the end he doesn't want to inherit my new welder :)

Gadget
02-26-2011, 08:23 AM
I'm no electrical engineer but I think you would be better off driving a good ground as close to the welding table as possible and connecting that to the welding table. I've read that's the safest way to do it.
As for welding in flip flops, the first time you get a ball of molten metal on your foot you will switch to leather shoes. Also, don't get any shoe that has a seam on the toe box, that can collect hot metal and burn through. Believe me, it hurts.

SICFabrications
02-26-2011, 02:55 PM
ok, wow..... first off, lets see.... guy comes on asking a question about wiring. gets answers and then starts an argument about eh advice given and states fact in regards. why even ask the question to begin with? to answer your question, spyguy, ALL 220/ 240 single phase machines are 2-wire hots. the 3-phase machines throw in a red hot for the third leg. on the 220 machines, they are black n white. hope that helped...


mcaz, the only reason you would need to ground your table to the ground rod is only if you are frying your computers and other sensitive electronics when using hi-freq AC tig. ive yet to ground a table and been doing this for alotta years. the biggest thing, is my welders are running off a different service than my house or anything else for that matter. well, let me clarify that.... my shop is on seperate service. i am running a very large break and shear, several welding machines and lathes, drill presses and the likes... i have 3 110v outlets in the office that are running from the house service for the computers and charging batteries etc...

like i said earlier tho, you will only need to ground the table if you are using hi-freq ac tig and you fry stuff inside the house. and then, the table and the lug from the back of the machine should tie into the same grounding stake... all this does is eliminate the electrical "noise" that hi-freq AC makes... hope that ive helped you out as well....


on a side note, dont be a goober, wear proper PPE while welding, please.... last thing i wanna read about is some knucklehead caught his house on fire because he was wearing flip flops, dropped a pile of slag on his shoe, took off running and let the stinger cable land on the hot weld and it melted through the insulation and short circuited out and caught the wiring on the wall on fire and burned the puppy down.... fyi, your homeowners insurance WILL NOT pay for the house if the fire was started because of welding... trust me on this...

---------- Post added at 03:55 PM ---------- Previous post was at 03:49 PM ----------

:edit...... all longevity 220/ 240 machines..... also, why follow the minimum requirements for wiring? if cost is that big of an issue, then you dont need to pick up welding as a hobby or business. leads for smaw will also give you a minimum chart over a certain amount of feet.... ive run the smaller leads that follow minimum reqs and have since switched out to larger leads, it actually allows the machine to perform better. now, i am running 2/0 leads 100 ft per side and a 1/0 stinger at 15 ft long. this allows my engine drive to give me the same amperage and ocv at the stinger regardless if i am 10 ft away or 300 ft away.

if you can afford the extra weight in copper, might as well do it, you might find an old transformer machine later and try to use it only to find that you would have to tear out all the work youve done and go back with larger service. that is experience speaking