Cosmo 130 Trips my electrics

[Mark G Cosmo 130]

Hi all

I'm new here, have been a few times in the past but never had to post a question before.

I have a Cosmo 130 and it is tripping my house electrics when used. I first thought it was just taking too much current when welding but I noticed yesterday that when I press the trigger without it touching my work piece it still blows.

I'm assuming it'll be an issue with the wire feeder? I've read a couple of posts about wire feeder transformer but to be honest it pretty much confused the ass off me!

Is it likely that this mod will fix my issue or perhaps it could be something else?

p.s. I haven't used my welder in this house before, I only moved here in Jan and haven't had reason to use it since moving in so could it maybe just be a case of an over sensitive trip?

Many thanks in advance.
Mark.

 

[rtbcomp]

Welcome to the forum.

Is it the RCD (earth leakage trip) or an MCB (too much current) that's causing the problem?

 

[Mark G Cosmo 130]

Good question, it looks like its an RCD trip.

Thought its worth mentioning that it will actually lay down a weld. It only trips on every 2nd or 3rd go, Extremely annoying when trying to do some tack welds.

 

[Wedg1e]

Sounds like a typical inductive spike - just one of those things when switching on a big transformer. You may have to modify or change the distribution board to a split type and run the MIG from the non-RCD monitored side.

 

[rtbcomp]

Good question, it looks like its an RCD trip. We need to know for certain. If you're not sure is there any chance of a photo of the trip device?

 

[Mark G Cosmo 130]

The welder is blowing green RCD protected switch 3 - sockets

So it says rcd protected, I assume this to mean its an rcd trip.

 

[Mark G Cosmo 130]

Sounds like a typical inductive spike - just one of those things when switching on a big transformer. You may have to modify or change the distribution board to a split type and run the MIG from the non-RCD monitored side.

Oh yea, just what I thought!?

 

[brightspark]

The welder is blowing green RCD protected switch 3 - sockets

So it says rcd protected, I assume this to mean its an rcd trip.

the residual current device is the one on the righ hand side is it one of the minature circuit brakers that is tripping and what current rating is stamped on it. is it a 16 amp or a 20 amp or 30 amp and it also tells u on it what type either a b type or a c type . will more than likely be a b type been a domestic board

 

[Mark G Cosmo 130]

Closer photo of the box.
The one blowing is number 3.

 

[brightspark]

it wont take much to knock a 16 amp breaker out with a wire wound transformer on start up. u could increase it to a 20 amp c type max is the welder plugged in to a 13 amp plug /?

 

[Wozzaaah]

How many sockets does that MCB feed and what else is plugged into them?

 

[wheresmejumper]

id check for loose connections in the welder or plug if its blowing without arcing

 

[Wedg1e]

Oh yea, just what I thought!?

Transformer = two coils of wire wound on a shared (usually iron laminate) former. Current flowing in one coil induces a current to flow in the other. At the precise moment when you energise the 'primary' coil (pull the torch trigger) it creates a lage surge of current in the incoming supply wires; this 'spike' gets detected by your protection device (MCCB, RCD) which sees it as a momentary fault condition and causes it to trip. All transformers do this; toroidal (doughnut) types are worst though MIGs don't tend to have big toroidals.
As Brightspark says, the existing 16A breaker has a 'B' response curve; this means that an initial spike above a certain value will cause it to trip even though when running the AVERAGE current taken by the MIGs transformer will be within the 16Amps at which the breaker is rated. A 'C' or 'D' curve breaker will have a slower response to the transient spike so won't trip - at least not until the average current exceeds 16A. As he says, upping it to a 20A breaker and opting for a 'C' curve may be all you need to do - about a tenner from your electrical distributor (try to get one of the same make as different makes can be dimensionally slightly different).

Your distribution board already is a split type

 

[Mark G Cosmo 130]

I wonder if it may be worth running an extension lead from an upstairs socket and trying that as it looks to be a higher rating trip.

On the circuit that blows it runs downstairs, so kitchen appliances inc 2 freezers and a fridge etc.

 

[Wozzaaah]

^ I think that answers your question!
You've already got a fair few things running from that MCB and the welder tips the load over the limit and trips it.
I'd imagine if you unplugged every other thing fed by it the welder would work fine.
Sounds like you need to uprate it but I'd suggest you get a spark in to check the circuit is up to it for safety's sake.

Try the extension lead but make sure it's a heavy-duty one, is as short as you can get away with and is fully uncoiled.

 

[Mark G Cosmo 130]

I've got a decent lead that I've used for welding on many occasions, I'll try that when I get a chance and let you know how I get on.

I'll also try turning off the freezers and fridge and see if that helps.

Glad that its not a problem with the welder, I thought last time I used it that I had finally got to grips with it.

Thanks all.

 

[Mark G Cosmo 130]

So I tried it again today off the upstairs sockets and it worked without fault so looks as though its just a weak trip.

Cheers for your help guys.