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Jock_Jock
18th September 2004, 05:11 PM
I couldn't resist purchasing a near new CIG Compact Welder from Cash Converters the other day. I don't weld but it was a good buy and you can never have too many tools but.... when I tried it at home all would go well for a few minutes ie the welder would do its thing and i would begin my shaky attempts to weld but if i tried to runa bead for any more than a few seconds the power would cut off courtesy of the earth protect device in the main switchboard. I even tried it with a HPM earth leakage powerboard. Same result(except it only stopped power to the welder and not the whole house). Is this normal. It is rated for use on a 10 amp plug.
Is it buggered and hence the reason for it being cheap or am I doing something wrong?

If this post is in the wrong place I'd be more tahn happy for someone to move it.

Cheers
Jock

ozwinner
18th September 2004, 08:55 PM
Hi

I run my 15 amp welder through a 10 amp outlet with no probs ( yeah I know ).
But it never cuts out, unless I run it through one of them power boards with the 10 cutout switch on it.
Maybe you house fuse box has only 10 amp trips on it, this would make it trip.

Al

Marc
18th September 2004, 09:44 PM
Hi Jock.
What sort of welder did you buy?
CIG is the brand I suppose, so it is an arc welder or a MIG welder?

The ammount of heat you need to weld depends on the thickness of the steel and the thickness of the rod or wire you use. Heat is equal to Amps and amps are rather limited in a 10 amps home situation.

To weld with an arc welder an get good results is a bit of an artform, a MIG will be much more forgiving but both need lots of juice, specially if you are new at welding (and decided to weld a 4" pipe to a railway rail) :D

Try to experiment with small exercises, like welding two flatbars say 19x4mmm
flat, forming a T, with a 2mm rod and the amps as low as possible. Crank the heat up slowly untill you can do the job and the fuses hold. If you have a MIG, check the size of the wire and speed of feeder. Thick wire and high speed will require more amps and blow your circuits.

Cheaper and smaller welders tend to use more amps than a bigger (whithin limits) machine, for the same job. In general, if you want to venture into metal work, you will be better off with a 15 amp line direct from your board

soundman
18th September 2004, 09:59 PM
If its droping the earth leakage ,it probably got a problem. Take it back.
BTW it probably not safe to use either.

vsquizz
18th September 2004, 10:17 PM
If its droping the earth leakage ,it probably got a problem. Take it back.
BTW it probably not safe to use either.
What soundman said, its got a problem, back to CC or a welding repair shop.

Cheers

johnc
19th September 2004, 12:02 AM
What soundman said, its got a problem, back to CC or a welding repair shop.

Cheers
I would get that welder checked, but sometimes those circuit breakers will cut out at low amps, if its still playing up after a check maybe get the breaker tested. I run an old 15amp welder off a 10amp outlet also and don't have any trouble. However the toaster used to blow the breaker on its circuit everytime, turned out to be just a faulty breaker and a replacement fixed the problem. In the good old days some mugs just wacked in heaver fuse wire or worse still a 2" nail, it works fine until you either zap yourself or burn the house down.

Happy testing, JohnC

DanP
19th September 2004, 01:49 AM
Jock,

Try turning the amps down before you assume the worst. Can you give more detail as to what type of welder, ie; does it weld with a rod or wire? Does it have a dial to turn amps down or just a switch indicating the size of the rod/wire? What are you trying to weld?

Dan

Jock_Jock
19th September 2004, 12:57 PM
Thanks for the input so far.
It is CIG's smallest arc welder (called the compact model) You alter the amps by turning a dial on the front and referring to a sliding scale on the top. I was just practising striking an arc and getting a good bead of weld down some 5 or 6mm mild steel plate. I was using a 3.2 rod at about 90 -100 amps.
I just checked the switch board and realised that when the welder tripped the circuit breaker it didn't trigger the rcd device as the power was still on to other parts of the house. the circuit breaker which tripped is only rated at 10 amps- perhaps a 15 amp is required.
Despite not tripping the house rcd it did contiually tripp the earth leakage hpm power board when i actually tried to weld something for any more than about 10 seconds.
I think I'll ring CIG tomorrow!

Marc
19th September 2004, 01:35 PM
Jock, a 3.2 rod needs well over 90 amp to melt properly, and the peak is when you get your arc started. 90amp x 50v = 4500 watt / 240 = 19 amps,

This drops down when you weld, but if your hand is not steady the rod will be starting and stopping (spatter) and the amps go throug the roof. Try a 2mm or 2.5 rod you will get better penetration. In any case, welding with a small arc welder on a home wiring is a compromise in the best of cases.

DanP
19th September 2004, 03:26 PM
Jock,

If you go down to a 2.5 mm rod you shouldn't have too much trouble. I welded with one of these welders at home for years and had no trouble. Try cranking the amps up to about 130 - 140 and see if you have any luck with the 3.2mm rod. I used to weld with 3.2's in a pinch with mine and still could do it. Run the 2.5 B/W 80 - 100 amps - experiment for your preferred amperage.

The size of the material you are welding is irrelevant to power draw. I have welded from 25mm thick material down to thin sheet. The only time the material thickness is relevant to what you are doing is when you are welding thin material and you need to keep amps down to avoid burning through.

Welding is not rocket science, if you practice correctly you will have it down in no time.

Dan

Barry_White
19th September 2004, 04:11 PM
Just as an aside as far as a 10 amp circuit goes it should have a 20 amp circuit breaker on it and if you aren't running any thing else on another powerpoint the breaker should hold with a 15 amp welder.

A 15 amp circuit still only has a 20 amp breaker on it but you are only allowed one power point on the 15 amp circuit which has a bigger earth blade on it but same wiring as a 10 amp circuit.

The only difference between 10 amp and 15 amp is the number of points you are allowed on the circuit.

So if the welder is tripping the breaker I would be getting the welder checked out.

Marc
19th September 2004, 04:23 PM
Hi Dan, I agree.
As for material thickness, with an arc welder that works on constant amps, it is the operator making the adjustments to amps manually. The thicker the steel, the bigger the rod, the more heat is needed and so up must the amp go or it does not weld so it is always a function of the thickness of the material to weld.
With a MIG welder that works on constant voltage, the power draw varies automatically according to the heat necessary to melt the wire and the parts to be welded. The more heat needed the more the amps go up and the wire comes faster to produce a bigger welding pool.

A drop in voltage due to a thin electric wire in the home outlet, will produce a weak bead and an overheated transformer, not to mention and overheated wiring if the fuse hold at all. Before using an arc or MIG welder at home, I would call an electrician to check the cable size and reinforce it if necessary and the same with the corresponding fuse or switch.

Barry, a 15 amp outlet has it's own line direct to the box and it's own cicuit breaker, you can have 4mm wire and 30 amp CB if you want.

Barry_White
19th September 2004, 06:09 PM
Hi Dan, I agree.

Barry, a 15 amp outlet has it's own line direct to the box and it's own cicuit breaker, you can have 4mm wire and 30 amp CB if you want.Marc
According to the SAA wiring rules you can actully have 2x15 amp plug sockets on 4mm wire with a 20 amp breaker but you can run a 15amp circuit on a 2.5mm wire on its own 20 amp circuit breaker as long as it is only one point on that circuit back to the board.

The other point would be if you had a very long run back to the board the 4mm cable my be required to reduce the voltage drop especially running a welder.

Marc
19th September 2004, 07:01 PM
Barry, you seem to know about electricity.
I am about to switch the house to 415 and the electrician asked me what sort of outlet do I want for the workshop if 4 pins or five. I did not know what to answer since I only know industrial motors with 3 fase or 3 fase plus neutral, never heard of 3 fase neutral and earth. Since i dont have any 3 phase motors yet, what should I do, or should i let it wired and install the outlets later?

Barry_White
19th September 2004, 08:49 PM
Marc

Normal 3 phase motors only have the 3 phases and an earth but do not have a neutral the only reason you would put a neutral with the connection would be if you had something like a 240 volt light that was operated in conjuction with the machine where you would connect it to one of the phases and the neutral.

The same as with a 3 phase air conditiong system where the compressor runs off 3 phase and the circulation fans run off 240 volts as the 240 requires a neutral.

So if you where only going to connect motors like a saw or a large planer/thicknesser you would only need 4 pole sockets eg: 3 phases and an earth.

Marc
20th September 2004, 10:53 PM
Thanks Barry, so 4 pins it is.

I noticed that we don't have 3 phase motors here without a neutral, that is 3 pins socket. :confused:

ivanavitch
20th September 2004, 11:36 PM
Jock
If your earth leakage circuit breaker (ELCB) is tripping then there is a problem with the welder. ELCBs work by sensing the current going out on the active (red or brown) and comparing it with the current coming back on the neutral (black or blue). If they aren't equal and opposite then there has been a current "leakage". This leakage is to earth. The leakage will be

a. back through the green or green yellow earth wire,
b. directly to earth, for example through the lump of metal sitting on the ground that you are welding, or
c. through YOU.

a. and b. could possibly pop a normal circuit breaker or blow your fuse.
c. can kill you.

ELCBs protect you from this form of fault. If you put yourself "in circuit" between active and neutral you will not be protected.

John Scott

ivanavitch
21st September 2004, 12:02 AM
Marc
It depends on the sort of motors you are using. Star or Delta. I'll try some ascii art

Star

A _______________
/ \
/ \
B ___________/ ____ \
C _________________|

E_____
|

Delta

A_______________
|
N______________ |
/ \
B_____________/ \
C ________________|

E_____
|

I'm not up on 3 phase commercial stuff so you would have to check on the motors that you intend to use. To be on the safe side go for a 5 wire connection, phases A,B,C neutral and earth. More expensive but it lets you connect either type of motor. Just drop the neutral wire when connecting up a star.

John Scott

ivanavitch
21st September 2004, 12:07 AM
bugger. ascii art don't work. all the spaces are removed. i hope you get the picture.

Marc
21st September 2004, 09:01 PM
Thank you Ivan !

glenn k
21st September 2004, 10:52 PM
My welder is rated at 15 amps but it can take up to 18amp but they are not allowed to say that or you could not use it.
Well it works fine in 10 amp power points but I have trouble with the electronic control if I use long extention leads. It makes noise the blows fuses or CB.
So try with out a lead and se if it helps, or closer to the house inlet.

vsquizz
22nd September 2004, 12:30 AM
With welders, always make the primary lead (supply to machine) as short possible. Its better to make the welding leads longer if needed. Not always practical but thats the way I was taught.

Cheers

Theva
22nd September 2004, 08:25 AM
Jock,

As per previous posts, if RCB or ELCB is operating is an earth leakage fault. If the welder was in storage for long periods then moisture may have got in and may cause the problem. Open it up & dry it out, if symptoms persist call a sparky.

Regards,

Theva