Stange fault on new installation

[Octopus]

>richy3333 - It's no different to a dual rcd protected property, as i say i was trying to reduce my final curcuit runs

>tony mc - The incoming ccu houses a wilex 100A main switch and 2x wilex 50A 30mA single pole RCBO's.

I have to disagree with you on that point. You would never put the downstairs sockets and lights on the same RCD would you?

 

[suffolkspark]

Ive split the house in the middle rather than by floors

 

[Octopus]

Ive split the house in the middle rather than by floors

So you have done it wrong. Read my previous post again

 

[tony mc]

Hi

I might be missing something here with your reply in post 15

IF it does turn out to be cumulative earth leakage i will have to expose the short vertical run in the stud wall and install some earthed mechanical protection, and fit a pair of rcd's into the consumer units.

If it is just overall leakage getting rid of the RCBO and placing one RCD in each of the CU is replicating exactally what you have now as far as the RCD is concerned re leakage!

 

[suffolkspark]

Pair of rccbs into each consumer unit sorry buddy trype it in in a hurry

 

[Octopus]

By splitting the house left and right across 2 RCDs you have meant your installation is not compliant with the regs.

Read part 9 again.

 

[richy3333]

Jeesus any need for that? As stated in post #1 the installation is TT so i would need some sort of RCD at the scource anyway even with SWA I'd need type S 100mA. Yes there would be discrimination but still could go out loosing the whole house.

IF it does turn out to be cumulative earth leakage i will have to expose the short vertical run in the stud wall and install some earthed mechanical protection, and fit a pair of rcd's into the consumer units.

Apologies if I have hit a nerve. If you want a cuddle you're on the wrong forum, but it sounds like you might be well out of your depth to me. No offence, but someone (a customer) is paying for this.

Would you care to state your qualifications and experience? The forum might be a place for advice but its not a substitute for correct/adequate training and experience.

BTW whilst I am not against an upfront 100mA RCD on a TT system can you please quote the Reg that requires it?

 

[suffolkspark]

I have 12 years experience, have relevant courses and part p all done properly but im not here to justify that

i would have fitted a dual rccb board at scource but did this to reduce long runs, there are socket outlet and lighting curcuits on each board serving both floors so you dont loose all sockets on say ground floor because of 1 rcbo tripping. Same goes for lights Maybe i hadn't explained that well because the circuits are spread well accross the ccu's.

I was of the understandig that a type s 100ma rcd was required on swa on a tt installation but if i am wrong please tell me?

I will be checking leakage next week, untill then theres nothing more we can discuss really so thanks all for initial advice

 

[Octopus]

i have a 2 way ccu with 2x rcbos, each serving a submain on 16mm t/e +10mmearth to a main switch / mcb board at each end of the barn (its huge!)

So you have 30mA RCBO's at source AND dual 30Ma RCD boards at each end of the property?

If this is the case, and the hob / oven are on separate RCD's, then I would suggest you've got the neutrals mixed up!

Or have I mis-understood your design and installation?

Just saying

 

[Deleted member 26818]

Hold up, it's quite common to split houses front to back or side to side, and to have a mixture of light and power on each RCD.
That way if an RCD does trip, not all the lights will go off.

 

[Octopus]

Hold up, it's quite common to split houses front to back or side to side, and to have a mixture of light and power on each RCD.
That way if an RCD does trip, not all the lights will go off.

But in this case he sounds like he has 30mA RCBO's protecting dual RCD board - one at each end of the property - so if this is the case not only does he have 2 x 30mA in series, and the fact that the RCBO's will 99% of the time trip out before the RCD on the sub board - turning off all the power to the "wing" of the building

 

[suffolkspark]

no rccb's in the sub boards those are main switch + mcbs sorry for being about as vague as humanly possible, if i could draw a diagram that would explain better.

either way im going to pin point the leakage next week, and if needs be i will protect the short bit of 16mm t/e in the wall. Remove upfront rcbo's and fit dual rcd boards in each wing as 4 rccbs then should allow for this leakage if it is indeed the appliances!

 

[Octopus]

no rccb's in the sub boards those are main switch + mcbs sorry for being about as vague as humanly possible, if i could draw a diagram that would explain better.

either way im going to pin point the leakage next week, and if needs be i will protect the short bit of 16mm t/e in the wall. Remove upfront rcbo's and fit dual rcd boards in each wing as 4 rccbs then should allow for this leakage if it is indeed the appliances!

Ok. Have you got an earth leakage clamp meter?

 

[Deleted member 26818]

Must be missing something then?
Post #19 states that if the fault is due to cumulative leakage then the OP will have to install earthed mechanical protection and fit a pair of RCDs into the consumer units.
Seems to be saying that there are no RCDs in the CUs at present?

 

[Octopus]

Must be missing something then?
Post #19 states that if the fault is due to cumulative leakage then the OP will have to install earthed mechanical protection and fit a pair of RCDs into the consumer units.
Seems to be saying that there are no RCDs in the CUs at present?

no, he is saying that each sub main and board are protected by a RCBO at source! So when the RCBO trips, the entire wing goes off