RCD Keeps tripping

[James9292]

I have recently added two double sockets in a lounge original nor realising that the source was a spur that someone had already wrongly spure, so two existing double sockets a spur from a spur I then added 2 sockets across the room on a back to back wall essentially creating 4 spurs which obviously tripped the RCB.After realising the mistake I added a 13A fuse before the first socket to prevent tripping and make the original sockets safer also so the order now goes spured power into 13A fused split to feet 2 sockets that in turn feed 1 double socket each. Unfortunately the problem has persisted I have tested all sockets with a fault plug and all register correctly wiring and no faults. I don't know if this is earth leakage from an appliance or RCB failure the main CU only has 2 RCBs one for lights and one for the entire ring Main B32 30mamp load and another B6 for the lights and 1 MCB each which seems minimal

 

[James9292]

I've had purchases an advanced kewtech plug tester that tests the loop and continuity also. Last night we turned off the power to the fused spur/s and it was still tripping does this mean that the fault has to be elsewhere? I am guessing at moisture or water in the outside sockets after this heavy rain etc!

And yes I don't have the full fluke or kewtech etc multimeters as I'm not fully qualified yet.

 

[LastManOnline]

I've had purchases an advanced kewtech plug tester that tests the loop and continuity also. Last night we turned off the power to the fused spur/s and it was still tripping does this mean that the fault has to be elsewhere? I am guessing at moisture or water in the outside sockets after this heavy rain etc!

Not necessarily. A fused spur only breaks the live, so a neutral to earth fault in the isolated circuit will continue to trip the rcd when sufficient load is flowing in the home. Neutral to earth faults are usually the most challenging faults to locate.

 

[johntheo]

Maybe remove the N & E from where the new fused spur is connected to "the other" spur.? or at least the N.

 

[James9292]

Maybe remove the N & E from where the new fused spur is connected to "the other" spur.?

I will try that but I have already rewired those connections and replaced the fuse face and socket face of 2 of the spurs on of which has a loose neutral connection point. But yes that sounds like the best way to confirm if the new wiring is the problem

 

[UNG]

I've had purchases an advanced kewtech plug tester that tests the loop and continuity also. Last night we turned off the power to the fused spur/s and it was still tripping does this mean that the fault has to be elsewhere? I am guessing at moisture or water in the outside sockets after this heavy rain etc!

Without an IR tester you are clutching straws as to where the fault is, personally I would try to narrow down where the fault is using an IR tester and depending on the IR level possibly use a cable tracer to home in on it

 

[timhoward]

Deleted

 

[MJPD29]

Would splitting the ring main onto more CBOs prevent th

What is the best way to trouble shoot that as I'm guessing it would be to go over all the new connections in turn also this happens every 4 to 6 hours or more sometimes with heavy load items ie kettles etc also happens under low load in the night

Best trouble shooting at this stage is to call a competent electrician. With all due respect a little knowledge can be dangerous and in this case you are making the installation much less safe with the work you are doing.

 

[James9292]

Best trouble shooting at this stage is to call a competent electrician. With all due respect a little knowledge can be dangerous and in this case you are making the installation much less safe with the work you are doing.

Thanks for all the response and advice guys and gals turned out it was a L to E fault from 40+ year old wiring degrading and unfortunately the fault is in the hard-core wiring not at any of the socket points or CU the multimeter was giving a reading of 50 to 90ohms at all socket outlets

 

[mechelec]

A spur from a spur wouldn’t trip an rcd.

an rcd or rcbo looks for an earth fault whereas an mcb looks for overload. (Nothing actually plugged in, no load)

you’ve done right by creating a fused spur, and by limiting the supply to 13A.

if the rcd trip is constant, check for a squashed cable behind a socket.

Does an RCBO not give earth fault and over current protection as well ?

 

[James9292]

Does an RCBO not give earth fault and over current protection as well ?

Yes that's why it's been tripping at increasing intervals for a week before refusing to turn on at all it is tested as functioning

 

[Intoelectrics]

Does an RCBO not give earth fault and over current protection as well ?

To be fair to Littlesparks, I don't think it was made very clear in the original post whether it was an RCBO or RCD with MCB's. I'm guilty of assuming it was a split 2 x RCD with MCB's CU.

 

[James9292]

To be fair to Littlesparks, I don't think it was made very clear in the original post whether it was an RCBO or RCD with MCB's. I'm guilty of assuming it was a split 2 x RCD with MCB's CU.

Very true, sorry but yes the tread has moved on originally a RCD tripping at intervals of 6hrs then 4 then every hour and then it refused to come on with the ring main mcb up due to a fault on the ring main now identified as the old part of the house with 1970s wiring and it's crumbling and melted together at the sockets on inspection resistance of between 50 and 90ohms

 

[James9292]

Very true, sorry but yes the tread has moved on originally a RCD tripping at intervals of 6hrs then 4 then every hour and then it refused to come on with the ring main mcb up due to a fault on the ring main now identified as the old part of the house with 1970s wiring and it's crumbling and melted together at the sockets on inspection resistance of between 50 and 90ohms

But no fault found at outlets concluded old had core wiring degradation

 

[Intoelectrics]

Very true, sorry but yes the tread has moved on originally a RCD tripping at intervals of 6hrs then 4 then every hour and then it refused to come on with the ring main mcb up due to a fault on the ring main now identified as the old part of the house with 1970s wiring and it's crumbling and melted together at the sockets on inspection resistance of between 50 and 90ohms

No worries, just for future reference, it makes it much clearer for readers to get an understanding of the situation if you can be accurate, clear and definitive in your description of the installation set up (type of earthing, CU type, type and rating of protection devices, type of wiring etc...).

 

[James9292]

No worries, just for future reference, it makes it much clearer for readers to get an understanding of the situation if you can be accurate, clear and definitive in your description of the installation set up (type of earthing, CU type, type and rating of protection devices, type of wiring etc...).

For future reference if your not a qualified expert your not going to know all that from the start if I was fully qualified I wouldn't have had to ask the questions or as you put it describe it all inaccuratly and as I stated the initial post has moved on

 

[Intoelectrics]

For future reference if your not a qualified expert your not going to know all that from the start if I was fully qualified I wouldn't have had to ask the questions or as you put it describe it all inaccuratly and as I stated the initial post has moved on

My post wasn't meant as a criticism, more as advice when seeking help. I appreciate you are still learning, I encourage my trainees to learn about all the protection devices. If they understand how they work and why they work i.e. what makes them operate this helps when diagnosing faults.

I have fell foul to not describing scenarios accurately before, and it has on occasion, made me feel embarrassed. My intention was to offer friendly advice, apologies.