Thread: Purchased Machienry houses Tig / Mig / MMa

I had a look at the standard that Unimig refer to in their technical document.

Originally Posted by AS60974.6

10.9 Attachment plug or appliance inlet
A supply coupling device shall be provided as a part of the welding power source and shall be suitable for the application. Its current rating shall be not less than the maximum effective supply current (I1eff.).
If an attachment plug is provided it shall comply with AS/NZS 3112. If an appliance inlet is provided, it shall comply with AS/NZS 60320.1.

The above quote clearly shows what Vernonv is saying and what I said way back at the start. The plug needs to match the Ieff value. If the Ieff value is greater than 15A then a plug capable of that Ieff value (and matching supply circuit) _must_ be used. Duty cycle is _already_ taken into account by this standard.

It's been pointed out, they will work on 15A circuits, just like a 15A airconditioner will work for a while off a 10A circuit. Maybe a long time. But it's not meant to.
If it goes wrong there is absolutely no come back if your insurance company says too bad mate.

I do not know how the manufacturer can justify their claim for 15A, I suspect if a customer was to approach them for written advice on how to operate their equipment continuously on a 15A circuit they would not give a firm answer.

SWK

Okay, let's do some comparisons. Magnum Mig Tig Arc 250 - 60% duty cycle at 250A - 15A supply
http://magnumweldersptyltd.vpweb.com...Mig-Arc250.pdf

Cigweld Transmig 250i 40% @ 250A - 15A supply
Transmig 250i (Power Source) - Cigweld - Victor Technologies Asia Pacific - South Pacific

Magmate Pro 250 30% @ 250A - 15 A supply.

Would you like me to go on?
Oh, by the way, a workshop I frequent just had an outlet wired in for a WIA 270C. For the benefit of Vernon, this was done by a licenced, certified electrician, facing Mecca and waving a chicken over his head to cover all eventualities. No "she'll be rights" here mate. Guess what? It was a 15A GPO. Who would of thunk it?
All sarcasm fully intended. I do not appreciate the insinuation that I am a cowboy.
15A outlets running high demand equipment do not appreciate dirty or damaged plugs and sockets or loose wiring. That has been the cause of more melted plugs than most things I can recall.
NONE of these welders draw maximum current @ 100%. Using the cable calculator I have, to AS 3000, 4MM cable will handle full load current of 42A and surge current of 84A over a distance of 25M.
I have not advocated running outside manufacturers recommendations at any time, other than the discrepancy between the two UNIMIG manuals. I have however compared several machines of similar performance that clearly state a 15A supply is adequate. Don't like the answers, take it up with MagMate, Migomag and Magnum Welders.

Originally Posted by Karl Robbers

I have not advocated running outside manufacturers recommendations at any time,

If you have suggested he fit a 15A plug then yes you have.

Originally Posted by Karl Robbers

I have however compared several machines of similar performance that clearly state a 15A supply is adequate. Don't like the answers, take it up with MagMate, Migomag and Magnum Welders.

Then maybe he should have bought a MagMate, Migomag and/or Magnum that is already fitted with a 15A plug ... but he didn't.

Those comparisons don't mean anything. Here are the FACTS:

1. The manufacturer doesn't fit a plug to the machine.
2. The manufacturer says that the machine needs a plug rated at least 25A.
3. The Australia Standard also says the same.

What more do you need? This is all very black and white.

The fact is if the machine is not hardwired (and installed according to the standard) or fitted with at least a 25A plug (as per the AS) then it is a sub-optimal and most likely an illegal installation. This is regardless of what other manufacturers have done, or what you have seen or heard done.

Originally Posted by Karl Robbers

Cigweld Transmig 250i 40% @ 250A - 15A supply
Transmig 250i (Power Source) - Cigweld - Victor Technologies Asia Pacific - South Pacific

Just out of interest I had a look at this welder and low and behold you can only run this welder to 190A (MIG mode) if it's fitted with a 15A lead/plug. If you fit the upgraded CIG lead/plug (25A) you can use the welder within it's full range. Well I'll be .....

Don't know if anyone posting here is qualified to install electrical installations, but I am. I've also have had a lengthy discussion about this with an electrical safety inspector from the ESO.
I Know what I'm doing, do you?

Really there is no point discussing something as dangerous as electrical installations here. Even if its as simple as a plug. (I have seen some dodgy DIY set ups in 20years.)
Seek advice from suitably qualified tradesman. In fact that goes for any trade that requires a license.

Originally Posted by cwcarter

I Know what I'm doing ....

Well I would suggest you brush up on some of the AS/NZS standards, like the the one SWK quoted above.

Well I should inform the inspector to brush up on his standards and while I'm at it I might as well hand my licence over to you. A quick call to unimigs tech will also confirm to you a 15 amp will be fine. I'm sure he'd put it in writing for you.

The fact is these class of machines are sold with 15 amp plugs and are used Australia wide without problems.(wonder why that is? because they pass au standards) This one may not of had a plug fitted but hasn't got any different specs to anything else.
There's a difference in flicking through one standard and finding something then to actually combine it in conjunction with other standards.
Stop making things harder then they should be.

Originally Posted by cwcarter

A quick call to unimigs tech will also confirm to you a 15 amp will be fine. I'm sure he'd put it in writing for you.

There is no need. Their manual says that the plug must be rated at the welders Ieff (which is 25A).

Originally Posted by cwcarter

The fact is these class of machines are sold with 15 amp plugs and are used Australia wide without problems.(wonder why that is? because they pass au standards)

What rubbish. Look at the manual that Karl linked to (the CIG one) and it clearly shows 2 different specs (and max welding currents) depending on what plug/cable is fitted. This may be an "artificial" limit, but a limit none the less, specified by the manufacturer.

We now have, from multiple sources (including the actual manufacturer of the welder and the AS standard) that the plug must be rated at the welder's Ieff, yet you seem to know better and refuse to accept that.

Originally Posted by cwcarter

Don't know if anyone posting here is qualified to install electrical installations, but I am. I've also have had a lengthy discussion about this with an electrical safety inspector from the ESO.
I Know what I'm doing, do you?

FWIW

SA A Class licensed endorsed "All electrical work"
In the dim distant past worked as an inspector, more recently spent a year as an investigations officer where I visited burnt out houses.
(I have done more than that, but that's enough)

Using the cable calculator I have, to AS 3000, 4MM cable will handle full load current of 42A and surge current of 84A over a distance of 25M.

AS3000 stopped having cable ratings in it years ago. AS3008 is what you want for cable installations as it covers the differnet types of installation (free air, underground, in insulation etc). And just to be clear about it the _best_ rating you will get out of 4mm2 is (when it is suspended in free air) 37A single phase (Table 10 Page 50) or 31A (Table 13 Page 58)


Vernon seems to know what he is talking about

SWK

The standard you refer to is for welding equipment not exceeding 3.6kVA. (AS60974.6)
So that leaves us with the other reference of AS60974.1. That's no good either because thats for industrial use. We are using this machine for domestic use.
Back to AS3000 we go. There is no reason why we can not install a 15amp circuit (using AS3008 as well) for this machine. Yes you are limiting it, but I'm sure it would be ample for most home users.
Why eldse would manufacturers get away with this?
An example would be that your house has a maximum demand of 80 amps. You have 10mm mains cable. What do you do? Well you put on a 50Amp circuit breaker to protect the mains and limit over current.
An example for diversity is a normal domestic 12 kilowatt stove. Thats 50 amps!! This is only required to be protected by a 32amp protective device.
Maximum demand for welders in domestic use is calculated by assessment. This is also used to select a suitable final sub-circuit.

Well that is an interesting tactic ... AS60974.6 covers welders for the "layman" (but under 3.6kVA) and AS60974.1 covers welders for professional and industry, however this welder doesn't "seem" to fall in either category as it's and industrial welder being used by a layman.

Oh what to do? Does this means we can do anything we want? Some would say "Yes we can"!

Let's get serious for a moment and stop splitting hairs. Regardless of who is using this welder, it is designed for professional/industrial use, hence why the manufacturer quotes it as certified to AS60974.1. I think the standard still applies

Originally Posted by cwcarter

Yes you are limiting it

Bingo! We have agreement.

Originally Posted by cwcarter

An example for diversity is a normal domestic 12 kilowatt stove. Thats 50 amps!! This is only required to be protected by a 32amp protective device.

All you are doing is proving our point. If you run that stove with all elements on (not sure who would do that, but anyway), the breaker would go and you'd be waiting a long time for your food to be cooked.

The same would apply if you put this welder on a 15 amp circuit ... use too much power and the breaker goes. It's like having a Ferrari that you can't drive faster than 40km/h.

Originally Posted by Vernonv

Well that is an interesting tactic ... AS60974.6 covers welders for the "layman" (but under 3.6kVA) and AS60974.1 covers welders for professional and industry, however this welder doesn't "seem" to fall in either category as it's and industrial welder being used by a layman.

Oh what to do? Does this means we can do anything we want? Some would say "Yes we can"! No it allows a suitable qualified person to design a circuit for the machines individual use.

Let's get serious for a moment and stop splitting hairs. Regardless of who is using this welder, it is designed for professional/industrial use, hence why the manufacturer quotes it as certified to AS60974.1. I think the standard still applies AS3000 also splits domestic and commercial use because of intended use and duty cycle.
Explain to me then why the manufacturers can sell them with a 15 amp plug.


Bingo! We have agreement. Ive said this all along


All you are doing is proving our point. If you run that stove with all elements on (not sure who would do that, but anyway), the breaker would go and you'd be waiting a long time for your food to be cooked. The point Im proving is the circuit is still safe and protected under the standard.

The same would apply if you put this welder on a 15 amp circuit ... use too much power and the breaker goes. It's like having a Ferrari that you can't drive faster than 40km/h.

I use my 250amp welder on a 15amp circuit, ample power for what I use (up to 4mm aluminium). Most welders you hardly ever use flat out and if you do you wouldn't be welding very long.

Originally Posted by cwcarter

Explain to me then why the manufacturers can sell them with a 15 amp plug.

Ummm ... they didn't, hence why this thread was started ... and once again I will quote the MANUFACTURERS manual

Input cable connectionA. Connect the machine to 240V 1 Phase, ensure that the machine is fitted with a plug that is equal to or larger than the Ieff.

where Ieff = 25.4A. Highlighting is mine.

Deja vu.

Oh they do, not this particular one but others on shop shelves I have seen. And like Karl has stated plenty of other machines including mine.