Thread: 15amp plug on welder

I just got the sparky to run a 15A gpo just for the welder. Cheaper, easy and safer
cheers
Pete

Originally Posted by wafarmer

If the electrician has done his job properly the wire should be rated to carry a load in excess of the breaker

My point was regarding manufacturer's seeking to avoid their responsibility to repair equipment under warranty due to a modification to the plug that has no impact on the performance of the machine. If they were *really* acting on safety grounds, they'd simply agree to fix the machine under the proviso that the customer would be charged for replacement of the modified plug/lead.

But as you correctly identify, the fundamental concept underlying the rating of circuit breakers is that they are there to protect the cable in the circuit, regardless of what shenanigans a punter does at an outlet of a circuit, if a fire is caused by cabling overheating it can only be due to either the cabling being under-sized, not correctly de-rated due to environmental issues such as running under insulation, or having the wrong amperage breaker.

Why? Because while it may appear inappropriate to modify a 15A plug to go into a 10A socket, you could just as easily plug in two ordinary 2400W fan heaters (with ordinary 10A plugs) into a double power point, placing far greater load on the circuit than the 15A device would.

The only significant difference between these two scenarios is the design of the power point. The socket of a 10A power point may not be able to handle the current of a 15A plug, but given the size of the active and neutral pins is identical on both a 10A and 15A plug, it's hard to see what the difference could be.

All that said, this discussion should not be seen as an endorsement for modifying or bypassing the systems and standards of our electrical regime - they are there for good reasons, informed by both theory and experience. Rather, I believe that for those who want to learn, it's useful to understand the principles behind the standards.

Incidentally, if you have 2 15A outlets on the same circuit, the breaker on that circuit should be 20A or 25A, and the electrician will have used thicker cable than the 2.5mm2 used for normal power circuits.

Originally Posted by fxst

I just got the sparky to run a 15A gpo just for the welder. Cheaper, easy and safer

No argument with doing it the right way

It's amazing how many times this subject has been raised on the forum and still brings in the comments from the members.

And I'm still amazed at the number of people that think their house wiring is going to melt and burn the house down. Fuses are there to protect the circuit, if your house wiring is glowing, a 15A welder is the least of your concerns.

Well once I was staying in a caravan in a friends yard and some how I was welding while my wife used a few appliances in the van . maybe Fridge , jug , toaster all running of one 10 amp extension cord into a power point in the house .Well there was a big bang and there was a big melted burnt hole in the power point and the end of the cord was a molten lump. Didnt blow a fuse though .

Where we live now Ive had friends stay in the same van up in the bush and melt the cord to the van so u couldnt get it off , the extension cords together so u couldnt get them apart , the cord catch on fire and burn through a couple of times and the cord melt onto the powerepont in the shed so its stuck on permanently .Didnt blow a fuse as it used to have a electric stove range hard wired to the cable the power point is on now . So some how sometimes things melt before the fuse goes .

Originally Posted by murray44

And I'm still amazed at the number of people that think their house wiring is going to melt and burn the house down. Fuses are there to protect the circuit, if your house wiring is glowing, a 15A welder is the least of your concerns.

So very true.
The size of the earth pin on a power plug has absolutely no relation the the actual current demands of the machine. A simple standard 10A earth pin could carry 80A or more easily. The only reason for the larger pin on a 15A circuit is to differentiate higher power demands to power lines with fewer outlets. Providing a person uses their head a little there is no problem with running a 15A machine on a 10A circuit - from a safety point of view.
From a insurance or warranty point of view its a different story altogether. As has been shown in this thread there are some companies who will turn a blind eye to a modification such as filing an earth pin or replacing a plug altogether & other companies who won't.
There is 1 issue with doing this that i didn't read in this thread tho i may have missed it & that is 1 of the length of the modified power cable. With greater power consumption you get greater voltage drops over longer cable runs which can lead to increased heat buildup, particularly if the cable has been coiled during use. This is a not a good idea. If a person does choose to modify a power cable, keep it as short as it practically needs to be & don't coil any excess.

Hi,

Despite my earlier comments It is still best to install the appropriately rated power outlets for the machine as you will get a lot better performance from them.

Also thank you for one of the best forums around.

cheers

wafarmer

My two cents...
I was up at a large mine in WA's North (one of the big two miners in Aus) and went to get a caddy from there store and noticed that there 140 Kempi inverter had a 10 A plug. It dosnt come with one, so I thought that was strange, I noticed the welder had a label maker sticker on it saying down-rated to 130 A, so not too sure what the sparkys had done but it did seem gutless even compared to my 110 Amp BOC inverter (maybe just imagining it).

So maybe there is something you can do to your machines to make a 10 A plug legit. These big company's are VERY safety conscious so it should be a legitimate fix...

Personally I run my 190 Amp MIG on a modded 15-10 A extension lead at home all the time on full power with no probs.
Although I run a mobile welding business and never would consider using that cord at a customers house, just because of the "what if" factor. ( I use a generator with 15 A outputs).

I think it comes down personal (and informed thanks to these forums) decisions, we make our bed and lie in it.