Thread: Unimig multi 250 with separate wire feeder

Originally Posted by macmac

Hi Brendon, my sparkie friend haven't sent me a bill yet but definitely peer price. So is that mean that I should change the circuit breaker to lower amps? Also, u may mentioned that the sparkie installed two 32 amps outlets with the same cable. Is that good enough if I use the two outlets at the same time. I will mainly using for plasma cutting and welding.

I am probably going to upset somebody here.

Are you sure that your "sparkie" is licenced? If so, he wont be for long if anyone checks this out.

• He has installed two 32A (64A!!!) outlets on a circuit that is only rated at 32A
• It matters not that you are only drawing 15A from this outlet, you could draw the full amount, therefore all must be specced to handle this.
• All this using 4mm wire, which is marginal for one 32A outlet
• There should be a separate circuit breaker for every outlet at this level - even for 3 Phase
• Just how much power is coming into your house from the service lines? let's say you have 100A total available. Take off the 64A potentially drawn by these outlets and you are left with only 36A to run your entire house that may have electric hot water (15A), electric stove (20A), electric jug (10A). See the problem.
• NONE of this shenanigans was required, all you needed was a 15A outlet that you could have used for something else.

I would have grave misgivings regarding anyone who tried to sell me a 32A 240V outlet to do a job easily handled by a 15A outlet. Did you actually question him as to his reasons for using 32A outlets? You need to ask some very serious questions about your "sparkie" Possibly even contact your local electrical regulatory authority as this is sub standard and you may as well have done the work yourself.

Originally Posted by macmac

Hi Brendon, my sparkie friend haven't sent me a bill yet but definitely peer price. So is that mean that I should change the circuit breaker to lower amps? Also, u may mentioned that the sparkie installed two 32 amps outlets with the same cable. Is that good enough if I use the two outlets at the same time. I will mainly using for plasma cutting and welding.

that depends what you running but usually two different outlets need two different breakers you can not run two outlets off the same breaker it will trip it.
that's a big plasma cutter to need 32 amps ive never used one to date thats had that big of a plug

Originally Posted by Karl Robbers

I am probably going to upset somebody here.
Are you sure that your "sparkie" is licenced? If so, he wont be for long if anyone checks this out.

• He has installed two 32A (64A!!!) outlets on a circuit that is only rated at 32A
• All this using 4mm wire, which is marginal for one 32A outlet
• There should be a separate circuit breaker for every outlet at this level - even for 3 Phase
• Just how much power is coming into your house from the service lines? let's say you have 100A total available. Take off the 64A potentially drawn by these outlets and you are left with only 36A to run your entire house that may have electric hot water (15A), electric stove (20A), electric jug (10A). See the problem.
• NONE of this shenanigans was required, all you needed was a 15A outlet that you could have used for something else.

I would have grave misgivings regarding anyone who tried to sell me a 32A 240V outlet to do a job easily handled by a 15A outlet.

that's exactly right i don't think your sparkie was licensed and there's no way it can be legal with 2 x 32amp outlets running off your original service and running two on 4mm cable either .
Karl robbers is exactly right

Originally Posted by brendon17

that depends what you running but usually two different outlets need two different breakers you can not run two outlets off the same breaker it will trip it.
that's a big plasma cutter to need 32 amps ive never used one to date thats had that big of a plug

Not really, plasma cutters need lots of power and remember this is only 240V supply.
Our 100A lincoln plasma requires 24A on a 3 Phase supply, so needs this plug size, albeit a four pin version.
This whole operation has been a fiasco - grossly overspecced, doubled up outlets on an equally underspecced line. To add insult to injury - nothing comes standard with the fool dam plug type used anyway!
The sparkie should have lived by the rule of "don't play with things you don't understand"

Originally Posted by brendon17

that's a bit over kill if he welder was to have a fault wont that cook the welder instead of tripping the breaker?

The breaker is there to protect the cabling/circuit, not the device (ie.. welder) connected to the circuit. The device should have it's own internal protection.

Originally Posted by Vernonv

The breaker is there to protect the cabling/circuit, not the device (ie.. welder) connected to the circuit. The device should have it's own internal protection.

i know it is there to protect the cable,circuit and not the appliance connected but the welder should be on a 15amp plug not 32amp.what im trying to say is if the welder was to have a fault it might hurt the welder before tripping the breaker.
cause i know if i just paid over 2g on a welder i would not wont it cooking it self if it had a fault instead of tripping the breaker.
the sparkie should have had known that the welder only needed a 15 amp plug.

Originally Posted by Karl Robbers

He has installed two 32A (64A!!!) outlets on a circuit that is only rated at 32A

That's not the way it works. How many 10 amp sockets do you have on the one power circuit at home? I bet it's more than 2 and I'm guessing the CB would only be 20A.

I don't have the info in front of me and it's been a while since I looked at it, but I seem to recall that you can have up to 2 x 20 amp sockets on a 4mm2 cable protected by 32 amp CB. Sorry I can't recall if it's the same for 32 amp sockets.

I'm not saying this install is ok or not, as there are lots of things that need to be taken into account in determining if things have been done properly.

Originally Posted by brendon17

i know it is there to protect the cable,circuit and not the appliance connected but the welder should be on a 15amp plug not 32amp.what im trying to say is if the welder was to have a fault it might hurt the welder before tripping the breaker.

The welder is supposed to be connected to AT LEAST a 15 amp circuit/socket. You say you understand that the CB is there to protect the circuit and not the appliance, but in the next breath, you say it should also protect the appliance.

If there is a fault in the appliance then the appliances internal fault protection will protect it. The circuit protection doesn't need to.

Originally Posted by Vernonv

The welder is supposed to be connected to AT LEAST a 15 amp circuit/socket. You say you understand that the CB is there to protect the circuit and not the appliance, but in the next breath, you say it should also protect the appliance.

If there is a fault in the appliance then the appliances internal fault protection will protect it. The circuit protection doesn't need to.

its just how i typed it i know the breaker is there to protect the circuit but its all so there to protect the appliance as well

Originally Posted by Vernonv

That's not the way it works. How many 10 amp sockets do you have on the one power circuit at home? I bet it's more than 2 and I'm guessing the CB would only be 20A.

I don't have the info in front of me and it's been a while since I looked at it, but I seem to recall that you can have up to 2 x 20 amp sockets on a 4mm2 cable protected by 32 amp CB. Sorry I can't recall if it's the same for 32 amp sockets.

I'm not saying this install is ok or not, as there are lots of things that need to be taken into account in determining if things have been done properly.

when my sparkie came to wire up my shed he installed 2x 32 amp outlets (one on one side of the shed and one on the other side to avoid extension leads) with 6mm wire and said each outlet needs it own breaker. He told me it very unlikely i will have the two outlet running at the same time but its better to have them on different breakers in case i was to have to appliances running at the same time to save headaches and money latter on.

Originally Posted by brendon17

... but its all so there to protect the appliance as well

Ok, one last time - it's NOT there to protect the appliance at all, in any way. If anything, it's there to protect the circuit from the appliance.

Originally Posted by brendon17

when my sparkie came to wire up my shed he installed 2x 32 amp outlets ...

Like they say, there are many ways to skin a cat. What your spark did sounds very reasonable and thorough.
The point I was making was we are crucifying Macmac's sparkie without knowing all the facts about his particular install. For all we know, what he has done is perfectly fine and legal.

Now I even get more confused. So shall I ran another 4mm or 6mm cable for the other outlet?

It's really a question that a sparky who's up to date on the regs should answer. There's a couple of issues - the correct wire size for a 32A circuit, and whether you can have more than one socket on such a circuit.

My completely uninformed view is that you can have multiple sockets on the same circuit because, as you observe, in your situation you'll only be using one device at a time.

Originally Posted by Vernonv

That's not the way it works. How many 10 amp sockets do you have on the one power circuit at home? I bet it's more than 2 and I'm guessing the CB would only be 20A.
Don't forget that domestic loads are generally fairly constant as in few surge loads like welders and large electric motors starting.

I don't have the info in front of me and it's been a while since I looked at it, but I seem to recall that you can have up to 2 x 20 amp sockets on a 4mm2 cable protected by 32 amp CB. Sorry I can't recall if it's the same for 32 amp sockets.

I'm not saying this install is ok or not, as there are lots of things that need to be taken into account in determining if things have been done properly.

Not wishing to argue, but that most definitely is the way it is for 3 phase power supplies in Tasmania and I can see no reason why this would not apply to a 32A single phase supply.
I have been through the process of installing extra outlets, both 20A and 32A 3 phase and was told unequivocally that the rules were one outlet, one breaker.
I absolutely fail to grasp the logic of installing 32A outlets for 15A equipment, especially since any equipment will need to have a non standard plug fitted, producing warranty issues. Even less, the logic of putting two on a circuit wired with 4mm wire, which struggles at 25A let alone at a potential 64A.
Here is an extract from a manual I have:
"The power supply must be 240 V, 50 Hz, rated to carry 23A full load current and 132A inrush. The wiring must be 2 core plus earth and a minimum 7-strand, 4 mm² cross sectional area copper. For long runs larger wiring may be required."
I have run some figures through a cable size calculator, (to AS3000). Using a full load current of 64A and a surge current of 320A, (5X max current is the startup current for electric motors, welders can produce far higher surge currewnts), over a distance of 10M, to achieve the relevant voltage drop standards, the minimum cable size is 10MM.
This should explain why, for high rated outlets, one outlet, one breaker is the norm.
However you look at it, this is a questionable job.