Rcd tripping

[kjc]

Hi guys I have come accross a weird problem, a cooker circuit fed by rcd two trips rcd 1 when cooker in use . Both rcd's changed , check neutrals etc replaced cable . Even took of rcd but still tripping the rcd! Help

 

[Octopus]

New fuse board?

 

[Leesparkykent]

Test the circuit.

 

[richy3333]

New fuse board?

Rubbish idea, I'd suggest a full rewire, including the neighbours house, to be on the safe side

 

[Octopus]

Rubbish idea, I'd suggest a full rewire, including the neighbours house, to be on the safe side

Ha ha. I meant has a new one been installed?

 

[Rappid]

Let's take a step back, was this a fault you was given today or as a result of some recent work, a new circuit or consumer unit?

 

[spadders]

Dodgy element?

 

[kjc]

Ha ha. I meant has a new one been installed?

Tested , new circuit, newish board not by me , pyro supply tncs, took of rcd but still trips rcd???? Neutrals all correct ect...

 

[kjc]

Defo not the cooker , nor circuit . Was a fault I was called out for , not rcd or neutral at board

 

[Darkwood]

List all your tests and results ... otherwise your wasting our time, without them we will all just be guessing.

Have you done a ramp test
Have you done a full RCD test
Have you insulation tested the associated circuit(s) to the rcd ??? Please give results and what circuits the rcd covers, have you disconnected physically the other circuits L & N to try isolate the issue if more than one circuit common to rcd.
Have you checked for crossed N in the board or borrowed N in the install

Please provide everything you can as it could be many causes and we end up going in circles.

Firstly though disconnect all circuits physically - adding the cooker first then try it, add each circuit there after until the problem re-occurs if not tripping with cooker only, possible N/E issue on unrelated circuit and the loading of the cooker is enough to show the issue.

 

[Pete999]

Switch the cooker OFF switch all the boiling rings, oven and grills OFF and switch the cooker back on, now switch all the rings oven and grills back on one at a time until the RCD trips.

 

[Octopus]

Defo not the cooker , nor circuit . Was a fault I was called out for , not rcd or neutral at board

So why do you say its the cooker tripping the RCD?

I'd be getting out my clamp meter to check the accumulated leakage!

 

[Deleted member 9648]

Defo not the cooker , nor circuit . Was a fault I was called out for , not rcd or neutral at board

Defo not the cooker,circuit ok....rcd ok....neutrals at DB ok, well it wont trip then will it......Oh hang on a minute,it does trip though doesn't it?

 

[dmxtothemax]

Hi guys I have come accross a weird problem, a cooker circuit fed by rcd two trips rcd 1 when cooker in use . Both rcd's changed , check neutrals etc replaced cable . Even took of rcd but still tripping the rcd! Help

Have you tried diss-connetting cooker 1 then testing cooker 2 ?
Could be something funny going on in cooker 1.

Remember the neutrals and earths must be 100% ok and seperate
Or the rcd's will do funny things.

One rcd could be more sensitive or quicker than the other.

 

[UKMeterman]

Check for N-E faults anywhere in the installation, particularly on the side RCD1, cooker puts a big current through the N to the sub, this then causes N to rise with respect to E depending on the resistance of N this then causes an imballance to RCD 1 then click..

 

[davesparks]

Check for N-E faults anywhere in the installation, particularly on the side RCD1, cooker puts a big current through the N to the sub, this then causes N to rise with respect to E depending on the resistance of N this then causes an imballance to RCD 1 then click..

Eh? You've got serious problems if the neutral is rising!

A N-E earth fault will simply divert a portion of the normal neutral current to earth via the fault. This is why an uncleared N-E fault can be very very dangerous

 

[bigdavs83]

Going back to the OP am i right in thinking you are saying the cooker is installed on one side of a split db fed from an rcd and there is another rcd on the other side of the split board which is the one that is tripping? Is rcd 1 fed from rcd 2? Is the discrimination the correct way round?

 

[davesparks]

Going back to the OP am i right in thinking you are saying the cooker is installed on one side of a split db fed from an rcd and there is another rcd on the other side of the split board which is the one that is tripping? Is rcd 1 fed from rcd 2? Is the discrimination the correct way round?

Yes he has said the cooker is supplied by one RCD but the other one trips when the cooker is used.

This is the normal and expected symptom of a N-E fault on one of the final circuits fed by this board (not necessarily the cooker circuit)

 

[bigdavs83]

Back to basics testing required me thinks. Remember it's just electrics at the end of the day. It's a live a neutral and an earth. Ma dad loves saying that to me!!

 

[UKMeterman]

Hi,
Have a read of http://www.beama.org.uk/download.cfm/docid/60FB5433-87E0-4244-B06CD4EC79EC737E