fuse blowing

[Peloquin]

It's cold and I'm bored so figured I might as well practice laying a pad and burn up a few 3.2 rods.
I've been happily making a pig's ear of some lovely flat steel for about half hour, stopping for coffee and wee break when I finished a run.
Went to start another and nothing..nowt.
I thought it was maybe the thermal cutout (if it has one) but the light was off, no power at all.
Checked the fuse and it had blown....
The welder is on about 105 with 3.2 rod.
Fuse replaced, I plug it in, it turns on fine and sits humming, all good. The instant the arc strikes it trips the main fuse in the house. Reset that expecting another blown fuse but it isn't, welder sits humming and ready.
I've tried it a couple more times but it trips house again.
Could it be the cut out our is it something more serious?
All the elections were installed by fully qualified sparky about 12 months ago and everything else works fine.
Cheers folks

 

[Appyasme1]

You are probably drawing to much current,drop you amps,use a 2.5 rod,see what happens

 

[daleyd]

What make and model of welder is it?

Have you tried turning the amps down to say 70 and try again?

 

[HughF]

It trips an rcd/rcbo in the house or an Mcb?

I assume it is the former if the fuse in the welder plug is still ok. This would point to an earth leakage fault in the welder, possibly caused by a component failing which took the fuse with it the first time.

 

[rtbcomp]

What exactly do you mean by the main fuse?

 

[Peloquin]

I know nothing about leccy. Sorry if I'm confusing people.
Main fuse is the main trip switch that cuts all power in the house.
It's a cebora mono welder.
I didn't try login power in case I was gonna knacker something.

 

[Peloquin]

The original earth lead was in a poor state so was unscrewed and replaced with a thicker cable from work with a better clip on it but that was ages ago and the welder never moves

 

[Appyasme1]

Trip switchers are good at what they do.They do not like any sort of power input rush.The old fasioned wire type fuses could stand this surge.I know this ststment will not help your problem but maybe put your mind at rest

 

[Appyasme1]

sorry for the spelling!!

 

[Peloquin]

sorry for the spelling!!

Better than my welding.Haha

 

[Appyasme1]

Nice one!!!!!

 

[rtbcomp]

...
Main fuse is the main trip switch that cuts all power in the house.
...

That'll be the RCD then

The original earth lead was in a poor state so was unscrewed and replaced with a thicker cable from work with a better clip on it but that was ages ago and the welder never moves

Assuming you mean the welding earth rather than the mains earth?

Make sure the welding earth is NOT connected to the mains earth and that the welder is standing on something dry and non-conductive.

 

[Appyasme1]

Sorry rtb I know that I will get in trouble for this but I have to say"SHOCKING"

 

[Peloquin]

All I've done is unscrewed the original cable and replaced it the same so everything should be the same. It's worked for months like that do wouldn't it have caused a problem before now?
And yeah, sorry, the welding earth with the clamp on

 

[Appyasme1]

Why not strip the cable back a foot or so

 

[Peloquin]

Which? The original? It was ********.
I put a pic up a fair while ago of the state the welder was in

 

[normspanners]

Are you running it off an extension ?? and was the ext still wrapped up ?

 

[Peloquin]

The sparky ran a cable from the house to the shed and put a socket on the wall so it's pretty much the same as plugging it in in the house. No extension.

 

[RonHopeful]

I had exactly this problem when I had my AC buzzbox. The power to the shed is on a spur from the ring main in the house. Any time I turned the amp up above about 110 amps, the rcd on the spur circuit would trip. Sometimes the fuse in the RCD would also blow and/or the fuse in the plug on the welder. Basically, I could only use 2.5mm rods. I looked into the possibility of upgrading the electricity supply to the shed but it was going to be too expensive. Instead I bought an inverter welder and haven't had any trouble since.

 

[RonHopeful]

Dunno. It's a box thingy with a fuse in it and a red button. I pointed at it once and said to someone "what's that?" They replied "it's an RCD". Perhaps they knew only marginally more than me. Sometimes it would simply trip - and I could push a little red button to reset it. But more often the fuse would blow.