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hi westward thanks for your reply
yes, the meter is above left of the rcd.
the 5th (far right) connection on the meter is the E7 live o/p, this goes direct to the E7 CU.
so what you see at the service JB, as you correctly point out is live & neutral from the rcd, live & neutral to the main CU, and lastly neutral to the E7 CU
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Need a wider picture of the full set-up. Something doesn't seem correct, assuming the service terminal block is outgoing from the rcd it has five conductors connected which seems wrong. It appears one conductor bypasses the rcd.
Is the meter above left of the rcd, I suspect the line to your E7 is not rcd protected but the neutral is going through the rcd.
you're quite correct, and this was how it was left after the new meter was fitted.
are you suggesting that i fit a second rcd for the E7 circuit, so that (as far as the E7 circuit is concerned) both live & neutral go via an rcd ?
 
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That is your problem. The line and E7 neutral are creating an imbalance as one uses the rcd while the other does not. If you have a TT system and that is the only rcd then the E7 circuits a not likely to have fault protection. The E7 needs a separate rcd with its neutral taken from before the current rcd.
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This is the set up you require.RCD tripping when E7 switches on 20191107_115355 - EletriciansForums.net
 
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That is your problem. The line and E7 neutral are creating an imbalance as one uses the rcd while the other does not. If you have a TT system and that is the only rcd then the E7 circuits a not likely to have fault protection. The E7 needs a separate rcd with its neutral taken from before the current rcd.
ok, that makes sense to me... and easily done, apart from taking the neutral prior to the current rcd .... there is no available (extra) connection point, unless i fit a JB into the incoming neutral line ?

will nip off and get required bits...
 
You need another single pole service terminal block. At this point you need the services of an electrician as you are touching wiring which strictly speaking can only be isolated by an authorised person.
 
You need another single pole service terminal block. At this point you need the services of an electrician as you are touching wiring which strictly speaking can only be isolated by an authorised person.
With all the past experience he has and the advice he has received from us I don’t think he will take your advice, as good as it is.
 
It's a pity we didn't have that pic to start with. The OP did stress that the only thing that had been changed recently was the meter, but I suppose we all overlooked something so blatant as the tails being connected up wrongly, which could never have worked.
 
The E7 line which bypasses the rcd does seem an alteration, black cable tie fitted. I suspect this has nothing to do with the meter change. I suspect when the rcd was fitted to replace the voltage operated device some time back the E7 was no longer in use so no problem was evident.
 
ok guys, thanks for all the advice, and I will be taking it. i have all the gear (and some idea :) ), so i will make the connections today, and if it all works ok, i will still leave the appointment for local sparks to come monday pm.... and he can check it over for cockups and poor workmanship, and sign it off ..... (hopefully) ...

i'll post results tomorrow ... should i still be alive ....
 
It's naughty, whichever way it came about. With any load on the E7 board, in the event of a trip the house blacks out, but every single point is still live, both on the E7 and the 24h and there is more risk of shock with the RCD off than on. It's a good thing it was self-incriminating.
 
It's naughty, whichever way it came about. With any load on the E7 board, in the event of a trip the house blacks out, but every single point is still live, both on the E7 and the 24h and there is more risk of shock with the RCD off than on. It's a good thing it was self-incriminating.
it's a good point.... but, as it stands, with the rcd tripped, the only live would be to the E7 cct, both live & neutral to the 24h cct would be isolated.
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That is your problem. The line and E7 neutral are creating an imbalance as one uses the rcd while the other does not. If you have a TT system and that is the only rcd then the E7 circuits a not likely to have fault protection. The E7 needs a separate rcd with its neutral taken from before the current rcd.
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This is the set up you require.View attachment 53677
great!.... got the bits, just consuming last supper (well, lunch actually) and i'll be at it !
 
as it stands, with the rcd tripped, the only live would be to the E7 cct, both live & neutral to the 24h cct would be isolated

No they wouldn't, if there's load on the E7 DB, that's why it's so dodgy. There's a path from E7 line, through the E7 load to the E7 neutral bar (which is now at 230V w.r.t earth), via the splitter block to the 24h neutral bar also now at 230V, through the 24h load to the 24h line. There's no circuit to supply neutral so none of the loads work and it all looks dead as a dodo, but every conductor in the installation is sitting at 230V via the loads. The resistance of a heater in series makes no practical difference to the severity of an electric shock. And there's no RCD protection.
 
I would get an electrician in to give the installation a thorough check. For your own peace of mind.
 
No they wouldn't, if there's load on the E7 DB, that's why it's so dodgy. There's a path from E7 line, through the E7 load to the E7 neutral bar (which is now at 230V w.r.t earth), via the splitter block to the 24h neutral bar also now at 230V, through the 24h load to the 24h line. There's no circuit to supply neutral so none of the loads work and it all looks dead as a dodo, but every conductor in the installation is sitting at 230V via the loads. The resistance of a heater in series makes no practical difference to the severity of an electric shock. And there's no RCD protection.
yes, unless all the mcb in the E7 CU are off
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I would get an electrician in to give the installation a thorough check. For your own peace of mind.
he was coming monday pm anyway... so (by law, i believe) i need to have it checked out for cockups and/or poor workmanship
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how better to spend a wet afternoon ....
neutral split via new JB, new rcd fitted (80a) new tails where needed.
ccts are independant of each other now, each with own rcd.
what can possibly go wrong ? :)
thanks for your help guys, hopefully SWMBO will be nice and warm tomorrow, and i'll have lots of brownie points ....
will report back in the morning
 

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ok.... system working fine (well, apart from the fact that i failed to switch on one of the heaters ... doh) .... i checked them at 4 this morning (and switched on the one i left off last night !).
So, big thanks to you guys... saved me a lot of time and money, although i will still get it all checked by Mr Sparks on monday.
on reflection.... i'm a bit ----ed off with whoever fitted the new meter, and left the system in a dangerous state, i'm just lucky that i had no loads on the E7 side and the mcb was off. AND it cost me £100 plus to remedy, on the plus side thankfully no-one got hurt....
thanks again
 

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