How is I1max defined?

[skotl]

No it won't include inrush current, it's maximum current it will draw in normal operation.

Inrush will be dealt with breaker type b, c, d,.

You won't get an inrush current as it's variable.

The effective is the RMS value I believe

Except when it does

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I still don't understand what problem is trying to be solved by the OP. I1Max is literally maximum current as defined by the manufacturer - so what other answer are we looking for

 

[Jack Ryan]

No it won't include inrush current, it's maximum current it will draw in normal operation.

Inrush will be dealt with breaker type b, c, d,.

Thanks, but I would like to get the standard's take on it. Without a proper definition, it would be impossible for a testing party to specify I1max.

You won't get an inrush current as it's variable.

The maximum value won't be variable.

The effective is the RMS value I believe

In a nutshell, I1eff is determined from the rated input current and the duty cycle of the welding machine. It is the value used to determine the required breaker and supply cable (and power plug/socket + mains flex).

The rated input current is the mains current drawn at the rated welding current. This is less than I1max which is why I assumed that I1max included inrush current.

Jack

 

[brightspark]

normaly they will state the full load amps you can calculate your supply cable size and breaker from that.standard breakers for domestic are b type, given the high inrush current it would require a c type .if its not clear phone there technical department up and ask

 

[Jack Ryan]

I still don't understand what problem is trying to be solved by the OP.

I asked because I would like to know the answer.

I1Max is literally maximum current as defined by the manufacturer - so what other answer are we looking for

Except it isn't - it is defined by a standard to which the manufacturer must comply.

Jack

 

[skotl]

I asked because I would like to know the answer.



Except it isn't - it is defined by a standard to which the manufacturer must comply.

Jack

Which standard? Which manufacturer?

This is just becoming a circular discussion, and I'm unconvinced by "I would like to know the answer" without a "why", so I'm out. Hope you get whatever you're looking for.

 

[mtt.tr]

What happens to the input current at the initiation of the arc?

The current can spike above the effective but can not exceed the maximum


Inrush will change depending on frequency of input voltage, the voltage and cabling resistance though inrush on inverters would be clamped with a PTC I would expect as the caps will take time to charge

 

[Jack Ryan]

normaly they will state the full load amps you can calculate your supply cable size and breaker from that.standard breakers for domestic are b type, given the high inrush current it would require a c type

Once upon a time, that was true. Now I1eff, part of the same standard, determines the required ampacity of the circuit.

I found the standard, it didn't help. I would need the compliance testing standard.

The thread has probably run its course.

Thanks for the help
Jack

 

[mtt.tr]

Except when it does

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When it comes to DC TIG welders, you won't find a more feature packed, performance driven machine than the Power i-TIG 200T. It's user-friendly interface is thoughtfully arranged, with an intuitive design that is charachteristic that people have come to expect from Everlast products. The Power...

everlastwelders.eu

----


I still don't understand what problem is trying to be solved by the OP. I1Max is literally maximum current as defined by the manufacturer - so what other answer are we looking for

Interesting an old school transformer can draw a healthy amount of current for a few ms

 

[Jack Ryan]

Which standard? Which manufacturer?

This is just becoming a circular discussion, and I'm unconvinced by "I would like to know the answer" without a "why", so I'm out. Hope you get whatever you're looking for.

The standards I posted earlier.
All manufacturers operating (manufacturing, importing and selling) in the jurisdiction of the standards.

 

[carbon]

Does this BOC au leaflet help

 

[Jack Ryan]

Does this BOC au leaflet help

Yes, thank you. It is what I quoted earlier and where I got the applicable standards from - IEC 60974 and AS 60974. It was the British version of the standard that I ended up finding.

Jack

 

[Turbo]

In a nutshell, I1eff is determined from the rated input current and the duty cycle of the welding machine. It is the value used to determine the required breaker and supply cable (and power plug/socket + mains flex).

Ieff gives you the minimum size for your supply, I would still be providing your supply according to the Imax figure to give you some headroom. If you are doing a lot of full power welding it will be better for the welder & likely give you a better duty cycle.

 

[Jack Ryan]

Ieff gives you the minimum size for your supply, I would still be providing your supply according to the Imax figure to give you some headroom. If you are doing a lot of full power welding it will be better for the welder

Well yes, it's the minimum but it also sufficient. You can always go larger but larger can be a lot more expensive, especially at I1max.

Welding machines are generally supplied with a power plug suitable for I1eff and the ampacity of cable that supplies the outlet is also set by I1eff. An industrial machine will have a higher duty cycle so, by definition, I1eff will be larger. The purpose of I1eff is to define the supply requirements with respect to ampacity and plug/socket requirements.

Only with long runs and with the use of extension cords might you need heavier cable.

& likely give you a better duty cycle.

The duty cycle of the welder is specified by the manufacturer based on the current carrying capacity of the components and the thermal conductivity of the heatsinks. Assuming the minimum requirements are met, increasing the capacity of the supply will not increase the machine's duty cycle.

Jack

 

[Turbo]

I fail to see why you started this thread when you've already made up your mind. You are ignoring sound advice myself & others have given you on this thread so I see no point in continuing to post in it.

So to quote Duncan Ballantine 'I'm Oot'

 

[Jack Ryan]

I fail to see why you started this thread when you've already made up your mind. You are ignoring sound advice myself & others have given you on this thread so I see no point in continuing to post in it.

So to quote Duncan Ballantine 'I'm Oot'

I'm sorry that the thread is beyond you and that you don't approve of my question. There is a lot of that on the Internet these days.

I have received some very good responses from others which I have taken on board and I thank them for it.

Perhaps it is time to let it lie.

Jack

 

[MRO Dept]

The answer can be found at NEC 630.12(B)...
I1max is the maximum value of the rated supply current at maximum rated output.
I1eff is the maximum value of the effective supply current, calculated from the rated supply current (I1), the corresponding duty cycle (duty factor) (X), and the supply current at no-load (I0) by the following formula:
I1eff = sqrt. of I1squared times X plus I0 squared times the difference of (1-X)

In the US, breaker sizing is based on <=200% of I1max, and conductors are based on >=100% of I1eff, for obvious reasons. (inverse time breakers often operate instantaneously, and conductors gradually warm up.) You need BOTH values for an installation.

 

[Jack Ryan]

The answer can be found at NEC 630.12(B)...
I1max is the maximum value of the rated supply current at maximum rated output.

Thanks. I think it is defined in other standards and used by NEC but yes, that is how I1max is defined..

The reason I was looking for a (precise) definition was because, although I could assume that I1max does not include inrush current, I wanted to see it in black and white. The source standard is reasonably well standardised across the world and the definition is:

I1max = the maximum value of the rated supply current (I1).

That isn't clear on the inclusion or otherwise of inrush current but the definition of I1 is:

I1 = the RMS value of an input current to the welding power source at a rated conventional welding condition

As the values are defined at a rated conventional welding condition, inrush current cannot be included.

I think that is as definitive as it is going to be.

Thanks for your thoughts and welcome to the forum.

Jack