Primary power requirements for WeldAll units

[SpyGuy]

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]

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]

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]

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]

they only need two hots and ground.

[KHK]

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]

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]

Today I called Longevity and confirmed that the WeldAll machines are all 2-wire w/ ground (2 hots + ground); no neutral required.

[KHK]

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]

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:



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.)