Rcd tripping at cu on new cooker install

[paramedicchris]

Just done a new install, new 40amp mcb at consumer unit, new wiring, new isolator switch and mounting point to a second hand cooker. However as soon as I turn it on it trips out, not at the mcb but at the rcd protecting the consumer unit. It sparks up the gas job part mine but the grill and oven immediately, trip the rcd. You get the on light come on at the cooker for a fraction of a second. Any thoughts guys? Problem with cooker? Was fine when last used at my parents, or something very obvious gone very wrong with the consumer unit?
Cheers

 

[BigJon]

Are you sure the neutral is connected on the correct side (RCD side) of the consumer unit?

 

[pjcomp]

And have you double checked the connections at all points - cooker, outlet, isolator - that you haven't crossed L and N somewhere? We can all do that in a senior moment

PJ

 

[jj4091]

Was the cct at your parents rcd protected? Has it been stood in a garage for a long time prior to you installing it?

 

[PrenticeBoyofDerry]

Did your parents have RCD protection on cooker circuit, when installed there?

 

[paramedicchris]

No rcd at the parents, just some good old fashioned fuse wire. Has been stood in the garage a while tho. Checked how I had it wired at consumer unit and its going through the rcd. Changed it so rcd no longer involved and its working. Bit worried that something is at fault with it to have triggered the rcd, or u reckon its just that it ain't designed to have one in the circuit, just a mcb or fuse? Cheers for all the help so far guys

 

[rjm2k]

Try some good old continuity testing on the cookerwith a multimeter between l n e while its disconnected from the mains?

 

[bernardgreen]

The ceramic /mineral insulation in metal sheathed elements that aare not being used can absorb moisture and the insulation between wire and the sheath becomes slightly conductive. After a long period ( months ) of non use this leakage can be enough to trip an RCD.

After a few hours of use ( on a non RCD protected supply ) the elements often dry out and the cooker can be put back onto the RCD protected supply.

 

[streetlighter]

Has the new final circuit for the cooker been tested for continuity of CPC, Insulation Resistance, Polarity, Earth loop impedance, RCD trip times ?
Sounds like you need an Electrician with the correct test gear to diagnose the fault.
New circuits and a special location like a kitchen comes under part P of the building regulations and should be notified or works undertaken by a part P registered Electrician.

 

[flyingsparks]

My money is on the neutral still being on the wrong side of the neutral bar. Op has probably just moved the live and mcb over to non rcd side and hey presto it's working. Photo of inside the consumer unit (with main switch off) would be helpfull

 

[joe-90]

Doing his own gas too, it seems.

 

[flyingsparks]

Doing his own gas too, it seems.

It's ok he's a paramedic so when it goes tits up he can mend himself!

 

[Click4]

if it goes wrong, then they will throw book at him in court.

But as of this moment in time, as long as it is not dangerously installed, and is installed to current regulations and in a safe and working order.. not sure he has broken any laws because last I checked a homeowner was allowed to do gas work in their own home, but not friends or relatives or anybody else's home for free or for money.

Only problem is, when people do DIY gas, they have no idea if they are doing it correctly or not, and more often than not, despite it being a building regulation that a Carbon monoxide alarm is installed during a new or replacement gas installation (if not already fitted) they often do not get installed.

 

[RF Lighting]

when people do DIY gas, they have no idea if they are doing it correctly or not

Just the same as electricity then. The other silent killer.

 

[ban-all-sheds]

There are crucial differences.

One, for example, is that you can't die in your sleep from invisible, inaudible, odorless and tasteless compounds arising from improperly consumed electricity.

Another is that although electrical faults can cause fires which start out small, even though those can and do grow, there isn't really any such thing as a small gas explosion.