Using Ground as a conductor.

[Joker11]

So I was just looking at my Tig 300/300. It has a 115v outlet on the face. It powers the water cooler pump.

Then I realized this machine has two hots and a ground. No neutral.

The only way to get 115v would be to use the ground as a return conductor.

Or am I missing a step inside the unit and in my head?

[Kevin_Essiambre]

Likely has a small 240-120 step down transformer built into it.

[ronsii]

Likely has a small 240-120 step down transformer built into it.

Yep, that's why the current limit on that outlet.

[ccawgc]

same power to the plug as what runs the cooling fan motor. plug is fused to protect the step down winding. its all part of the main welder transformer.

[yesindeed]

If its the one in this version of the manual, it gets fed off of transformer T2 on page 22

https://www.lincolnelectric.com/asse...oln3/im353.pdf

[Joker11]

Ok, so it is stepped down to 120v and then what? How does it return?
Or does the transformer have 60v and 60v over zero?

[ronsii]

Ok, so it is stepped down to 120v and then what? How does it return?
Or does the transformer have 60v and 60v over zero?

Ground is still ground the 120v is from A coil (loop of wire with two ends) on the xfmr... thus the outlet hot and neutral will each have one of those wires.... the current is not returning to the utility power source... well not in a direct way anyways

[Denis G]

You can have multiple secondary windings on a transformer: https://www.electronics-tutorials.ws...er-basics.html

Sometimes coils are center tapped.

[Willie B]

They kind of phased those outlets out. Efficiency & GFCI requirements would be my guess.

[farmshop]

Wouldn’t surprise me if they used the ground as the neutral. Many old electric panels just used a 3 wire system

[Willie B]

I used to wonder why they didn't build single phase welders with 4 wire systems. I never found an answer. They used secondary windings to produce 120 volt AC.

Equipment ground only connects to the frame.

[walker]

I have zero ideas about the wiring of that welder. However, welders, dryers, ranges, that had 120vac accesories used to use one hot and ground to provide the 120 volts for the secondary systems. This was prior to the 4 prong outlets. The only difference between the ground and neutral is semantics as far as the machine is concerned.

[danielplace]

Ok, so it is stepped down to 120v and then what? How does it return?
Or does the transformer have 60v and 60v over zero?

The Lincoln Tig 300/300 uses a completely separate transformer for the aux outlet power. It is not part of the main transformer but rater a separate control power transformer to step down what comes in to the 120 volt needed.

It is a transformer with normal neutral and hot on secondary. Returns on the neutral back to transformer.

T2 is control transformer. Line voltage in/120 volt out.

[Willie B]

I have zero ideas about the wiring of that welder. However, welders, dryers, ranges, that had 120vac accesories used to use one hot and ground to provide the 120 volts for the secondary systems. This was prior to the 4 prong outlets. The only difference between the ground and neutral is semantics as far as the machine is concerned.

Along with the occasional fatality, less often, fire.

In a properly installed system, Center tap (white) connects to earth ground at one point per house.
I can cite at least one case where a plumber was killed because someone considered ground & center tap to be equivalent.

Grounding (green, or bare equipment ground) is in many cases not securely connected, It passes through numerous connections, sometimes depending on a locknut not tightened on a painted surface. It only conducts electricity in fault circumstances.

Grounded, neutral, center tap, (white) is intended to conduct electricity. Conductors should always have insulation separating electrons from people.

I've seen many examples of arcing where somebody believed grounding was the same as grounded.

In New Hampshire a three conductor circuit supplying a household range was used when appliance delivery people replaced a range. The strain relief supplied with three conductor range cords NEVER fit. They discarded it and ran the cord through the sharp hole in the sheep metal with no protector.
They also failed to connect the bonding jumper. An arrangement I've seen hundreds of times. They then shoved the range between cabinets pinching the cord.

People living in the home never happened to touch the sink at the same time as the range. They were unaware the sharp knockout hole in the back of the stove had cut through insulation on the cord. It was live all the time.

A year or more later a plumber did touch sink & range at the same time. He had 120 volts left hand to right through his chest. He was killed.

[Willie B]

I have zero ideas about the wiring of that welder. However, welders, dryers, ranges, that had 120vac accesories used to use one hot and ground to provide the 120 volts for the secondary systems. This was prior to the 4 prong outlets. The only difference between the ground and neutral is semantics as far as the machine is concerned.

Earlier versions of code allowed three conductor cable to supply ranges & dryers with a list of conditions. Errors, or deliberate ignoring rules were so common, code was changed.

[Willie B]

The Lincoln Tig 300/300 uses a completely separate transformer for the aux outlet power. It is not part of the main transformer but rater a separate control power transformer to step down what comes in to the 120 volt needed.

It is a transformer with normal neutral and hot on secondary. Returns on the neutral back to transformer.

T2 is control transformer. Line voltage in/120 volt out.

The transformer in your diagram has no neutral. It's output is 120 volts. One terminal is equivalent to the other. If it were a 240 volt output with a center tap, you could call it neutral.

There is a lot of misunderstanding about the common 240 volt single phase grounded center tap systems. Because center tap is connected to ground, ground behaves much like center tap. In truth, as many electrons flow from center tap as "hot" legs in 120 volt circuits. You only use half the winding for those circuits.

[danielplace]

The transformer in your diagram has no neutral. It's output is 120 volts. One terminal is equivalent to the other. If it were a 240 volt output with a center tap, you could call it neutral.

There is a lot of misunderstanding about the common 240 volt single phase grounded center tap systems. Because center tap is connected to ground, ground behaves much like center tap. In truth, as many electrons flow from center tap as "hot" legs in 120 volt circuits. You only use half the winding for those circuits.

I did call it a neutral. Your right it is not actually a neutral. I used the word in place of return so it would make sense to those reading that don't understand all the terminology. Of course you and I and some others would know it isn't actually a neutral from a separate stand alone control transformer. It is just the return from the other end. Of course same load on neutrals as the hot on a circuit as it is the return of the circuit. One big ole' loop and it is all the same basically. Neutral will knock you just the same as the hot if you get in between the load and return or from load to ground.

[BaTu]

If you wanted to spend an hour and a half to explore grounding, there's no better resource than Mike Holt ->

[Willie B]

I did call it a neutral. Your right it is not actually a neutral. I used the word in place of return so it would make sense to those reading that don't understand all the terminology. Of course you and I and some others would know it isn't actually a neutral from a separate stand alone control transformer. It is just the return from the other end. Of course same load on neutrals as the hot on a circuit as it is the return of the circuit. One big ole' loop and it is all the same basically. Neutral will knock you just the same as the hot if you get in between the load and return or from load to ground.

No need to tell you. There, I'm preaching to the choir.
Others with less training, extrapolate from everything said to stockpile facts.

I dearly wish authors of code gave different labels to the center tap connected equipment. They call it "GROUNDED". After several years of sitting in a room trying to stay awake, an electrical apprentice begins to understand. Most of the population grab on to that root word, and presume they are the same.

Grounding & grounded are absolutely two different things. Your power company won't let you mess with their transformer, you don't need to concern yourself with the transformer.

At the "house" there is a service disconnect. Inside this first switch to turn off the power you need a "bond" connecting center tap to earth.
NOWHERE ELSE IN THE BUILDING, OR BUILDINGS SUPPLIED BY THIS SERVICE, SHOULD THERE BE A CONNECTION!!!!!!!!!

[Willie B]

If you wanted to spend an hour and a half to explore grounding, there's no better resource than Mike Holt ->

Mike Holt Knows far more than I will ever know. I deeply respect the man.

I suffer from severe insomnia.

Mike Holt is my personal cure for insomnia. He spends 45 minutes conveying less information than I send in a text.

[ronsii]

No need to tell you. There, I'm preaching to the choir.
Others with less training, extrapolate from everything said to stockpile facts.

I dearly wish authors of code gave different labels to the center tap connected equipment. They call it "GROUNDED". After several years of sitting in a room trying to stay awake, an electrical apprentice begins to understand. Most of the population grab on to that root word, and presume they are the same.

Grounding & grounded are absolutely two different things. Your power company won't let you mess with their transformer, you don't need to concern yourself with the transformer.

At the "house" there is a service disconnect. Inside this first switch to turn off the power you need a "bond" connecting center tap to earth.
NOWHERE ELSE IN THE BUILDING, OR BUILDINGS SUPPLIED BY THIS SERVICE, SHOULD THERE BE A CONNECTION!!!!!!!!!

I often wondered why not too many years ago I'd see people bonding the panels at every sub panel.... never really got a good answer out of any of them

Here's a small transformer we're helping put in up north, they take their grounding seriously!!! they show a 4/0 running the halo.. which is weird because they only have a 2/0 connecting to it and the rest of the ground buss...

[smithdoor]

It is odd to see but in old tube electronics you see that all time.

So what is voltage to ground.
It maybe have a center tap to ground so you have 57 volts to ground.

Dave

So I was just looking at my Tig 300/300. It has a 115v outlet on the face. It powers the water cooler pump.

Then I realized this machine has two hots and a ground. No neutral.

The only way to get 115v would be to use the ground as a return conductor.

Or am I missing a step inside the unit and in my head?

[danielplace]

I often wondered why not too many years ago I'd see people bonding the panels at every sub panel.... never really got a good answer out of any of them

Here's a small transformer we're helping put in up north, they take their grounding seriously!!! they show a 4/0 running the halo.. which is weird because they only have a 2/0 connecting to it and the rest of the ground buss...

That is all about lightning protection. They often require them to be cad welded right to the chassis.

[ronsii]

That is all about lightning protection. They often require them to be cad welded right to the chassis.

Yeah, have seen the cad welded stuff especially around telco buildings I believe these just called for some sort of crimp/screw/ connections. It was the 30' 4/0 ring around the base I though was a bit overkill

[danielplace]

I used to work for a company and one of our customers was Florida Power & Light. The major power company in most all of South Florida.

We did a lot of electrical jobs for them. One of them was installing new transfer switches/backup generators at all their company owned communications buildings/tower sites they have all over Florida. They required 4/0 for grounding of the generator bases and cad welded to the main frame and to the ground rods. Pretty neat whoever invented that attachment method. All the different molds they have for every kind of connection you want to cad weld together. That stuff is incredible the heat it develops when it lights off.