Plasma Cutter

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George Stolz

George Stolz

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I am grappling with a plasma cutter. Is this thing a welder? Does Art. 630 apply? Art. 670?

Supposing I were of a mind to put this thing on a 208V 3-Phase circuit. What on that nameplate do I pay attention to...? :blink:

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Article 630 applies. Says so right in 630.1 Scope. Electrical-supply-wise, treat it just like an arc welder.
 
But the demand factors in 630.11 only apply to arc welders. It doesn't say plasma cutters.

I could be wrong, but isn't a cutter more of a constant load than an arc welder?
 
steve66 said:
But the demand factors in 630.11 only apply to arc welders. It doesn't say plasma cutters.
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Well the only place any form of the word cut is used in the whole article is 630.1.... :?

I could be wrong, but isn't a cutter more of a constant load than an arc welder?
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It can be. But it can also be short duration, and intermittent also.
 
K8MHZ said:
Does being constant matter?

If you are talking about a continuous load, I would say no, as I doubt the cutter would be used without interruption for three or more hours.
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Not that kind of continuous load it has to do with the duty cycle of a welder or a plasma cutter basically the code allows you to cheat and run smaller conductors if the duty cycle is less than 100% you gotta take a look at article 630.
 
iwire said:
Not that kind of continuous load it has to do with the duty cycle of a welder or a plasma cutter basically the code allows you to cheat and run smaller conductors if the duty cycle is less than 100% you gotta take a look at article 630.
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630 is an odd one.

I. General (mentions plasma cutters)

II. Arc Welders (a plasma cutter is not an arc welder)

III. Resistance Welders (a plasma cutter is not a resistance welder)

IV. Welding Cable (a plasma cutter is not a welder)

Which section would apply to the duty cycle of a plasma cutter? I am not going for Part II, as it applies to a device, an arc welder. I. General applies to the use and distinguishes between arc welding, resistance welding and plasma cutting.

Common sense may dictate that Part I can be used, but I don't see Part 1 as having to do with plasma cutting. An apparatus for plasma cutting is not a welder. There is such a thing as a plasma arc welder, which is not the same as a plasma cutter.
 
what the heck is a "arc welder"

if its a "plasma cutter" then its not a welder, but essentially the machine are the same.

but there are plasma welders, gmaw, gtaw, smaw, etc,,,, all arc types :thumbsup:

there's also DC mode and AC mode too.

pick & choose and the power consumed varies quite a bit.


cutter vs welder in terms of constant amps draw? they will all show some form of "constant" when the specific machine is welding properly. having some skip with stick or poor settings with mig and you can see erratic amps profiles, etc.

3ph 208v needs 61A
 
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K8MHZ said:
As opposed to a resistance welder, AKA 'spot welders'.
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i was being funny ;)

so many types of arc welders. and deep down, all welding is a form or RW, even friction stir, some may use amps, others may not.
 
George Stolz said:
I am grappling with a plasma cutter. Is this thing a welder? Does Art. 630 apply? Art. 670?

Supposing I were of a mind to put this thing on a 208V 3-Phase circuit. What on that nameplate do I pay attention to...? :blink:
Click to expand...

My opinion.

Not a welder.

630 does not apply

670 does apply

670 requires max. current to be on nameplate, so I would go with 125% of 61 amps.
 
K8MHZ said:
Oxyacetylene welding isn't resistance welding.
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i disagree.

the atoms get hot from resistance of movement, which generates self-heat, then melts.
you are adding energy from the burning of gas, the burning gas does not actually melt the metal :thumbsup:
 
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