connick159 Posted May 12, 2023 Author Share Posted May 12, 2023 Thanks Dave. Great info! L jumper... Is it one of these? Link to comment Share on other sites More sharing options...
ProDave Posted May 12, 2023 Share Posted May 12, 2023 Not quite what you want. If you set up your top CU as that picture I copied from the linked website, you just need an additional 2 prong bit of busbar A bit of this You could buy a length and cut it down, but any electircian worth his salt will have odd bits of it lurking somwhere. 1 Link to comment Share on other sites More sharing options...
connick159 Posted May 12, 2023 Author Share Posted May 12, 2023 Ah yeah, got that. I meant to join the top cu and the bottom one. At the moment he has the live from the armour going into the main switch and "daisy chained" I guess you could call it straight down to the Main switch in the bottom cu (see pic). What I think you are saying is to use the 2 prong busbar to join then main switch in the top to the rcb next to to it. But... From that rcb (or was it mcb) do you then run a cable down to the lower cu so can do away with that "daisy chain" set up out of the top cu's main switch to the bottom cu main switch. He's coming back tomorrow arvo so gunna be an interesting chat. Thanks again. Sorry for all the questions. Must be annoying but I do appreciate the shared knowledge here. Link to comment Share on other sites More sharing options...
TonyT Posted May 12, 2023 Share Posted May 12, 2023 You shouldn’t have copper on show at the terminals. Is it worth glanding the Swa into a metal enclosure via some din rail terminals, transition to tails coming out straight into a pair of Henley blocks, then take 2 sets of tails from the Henley blocks to each db assume the Swa at the other end is in a kmf fuse switch or similar as the cutout is more than 3 meters away? that way every main switch only has one set of conductors in it and can be safely torqued to the correct setting Link to comment Share on other sites More sharing options...
ProDave Posted May 12, 2023 Share Posted May 12, 2023 19 minutes ago, connick159 said: Ah yeah, got that. I meant to join the top cu and the bottom one. At the moment he has the live from the armour going into the main switch and "daisy chained" I guess you could call it straight down to the Main switch in the bottom cu (see pic). What I think you are saying is to use the 2 prong busbar to join then main switch in the top to the rcb next to to it. But... From that rcb (or was it mcb) do you then run a cable down to the lower cu so can do away with that "daisy chain" set up out of the top cu's main switch to the bottom cu main switch. He's coming back tomorrow arvo so gunna be an interesting chat. Thanks again. Sorry for all the questions. Must be annoying but I do appreciate the shared knowledge here. Yes trying to get away from that abomination. When the top CU main switch is put back where it should be there will just be one L and N feed in to the top of it from the SWA feed. The N link down to the bottom CU will connect to the very top right high integrity N busbar. The L link down to the bottom CU will be fed from the MCB right next to the main switch. The input to the bottom of that MCB will be jumpered to the main switch with the short 2 section busbar. the original L cable coming out of it, which was supplied with the CU and splits in two to feed the two RCD's will also go into the bottom left terminal of the main switch with that short busbar. Link to comment Share on other sites More sharing options...
TonyT Posted May 12, 2023 Share Posted May 12, 2023 There's also the issue that MCBs tend not to discriminate with MCBs generally it's a bad idea to feed an Consumer Unit from an MCB in another Consumer Unit Link to comment Share on other sites More sharing options...
ProDave Posted May 12, 2023 Share Posted May 12, 2023 31 minutes ago, TonyT said: There's also the issue that MCBs tend not to discriminate with MCBs generally it's a bad idea to feed an Consumer Unit from an MCB in another Consumer Unit Cartridge fuse holder? Not sure you can get more than 32A though? Type C or D MCB? Link to comment Share on other sites More sharing options...
TonyT Posted May 12, 2023 Share Posted May 12, 2023 The Hager 701 can do 100amps but it’s wider than a mcb so would upset the ways in the CU. The main switch can only take 35mm2 max so doubling up is against the MI. From a cost saving point of view I think a metal enclosure with din rail terminals, Swa glanded into one side and tails coming out via an appropriate gland to a pair of Henley blocks- this then feeding both boards is the easiest way of making the installation compliant. then put rcbo for every circuit Link to comment Share on other sites More sharing options...
connick159 Posted May 12, 2023 Author Share Posted May 12, 2023 Aren't those pics of the dual rail CUs just the same as what I have had Frankensteined together? I.e. 2 din rails that need L and N transferred from 1 to the next? I know they are two separate cu enclosures but would then logical connection not be the same as the dual row in the link before? Link to comment Share on other sites More sharing options...
connick159 Posted May 13, 2023 Author Share Posted May 13, 2023 (edited) Update: he's not back till Sunday so while main fuse was out a swapped things around. Took out some mcbs and re did the way the RCDs were connected based on advice here. (Just top CU at this stage.) I put the lighting and socket circuits on the RCD as well as oven and hob. Put main fuse back in then turned it all on. Sockets and lighting both work without any trips like before. Result! There was a neutral being crossed from what I could see so once each RCD was on separate N bars prob resolved (I think) Will leave it there but thanks for all the help. Next challenge is having the WTF conversation on Sunday. New bloke coming for a look on Tuesday. Will give an update then for anyone interested. Cheers Edited May 13, 2023 by connick159 Link to comment Share on other sites More sharing options...
TonyT Posted May 13, 2023 Share Posted May 13, 2023 Well done mate! If you know he is busy at certain times ask him to come then, if he says can’t say don’t worry a guy at work can help.. give him a little out to make the conversation easier if you want or not!! Link to comment Share on other sites More sharing options...
ProDave Posted May 13, 2023 Share Posted May 13, 2023 1 hour ago, connick159 said: Update: he's not back till Sunday so while main fuse was out a swapped things around. Took out some mcbs and re did the way the RCDs were connected based on advice here. (Just top CU at this stage.) I put the lighting and socket circuits on the RCD as well as oven and hob. Put main fuse back in then turned it all on. Sockets and lighting both work without any trips like before. Result! There was a neutral being crossed from what I could see so once each RCD was on separate N bars prob resolved (I think) Will leave it there but thanks for all the help. Next challenge is having the WTF conversation on Sunday. New bloke coming for a look on Tuesday. Will give an update then for anyone interested. Cheers The fact your "electrician" could not figure that out shows his lack of competence. So progress at last. Quite probably all you have to solve now is getting a proper feed to the bottom CU without that over crowded mess in the main switch, allocating the circuits properly and testing them properly as you go, and getting some form of RCD protection to the bottom board. 1 Link to comment Share on other sites More sharing options...
connick159 Posted May 13, 2023 Author Share Posted May 13, 2023 5 minutes ago, ProDave said: Quite probably all you have to solve now is getting a proper feed to the bottom CU without that over crowded mess in the main switch... Yeah, thinking of splitting the armoured via one of those junction boxes (Henley block) I think they are also called. One.eqch for the N and L feeds and then sending one to top CU and then other to bottom CU. Then the rest as you say sorting out the config of circuits in the top CU and RCD (or RCCB) in the bottom. Thanks again all. 1 Link to comment Share on other sites More sharing options...
PeterW Posted May 13, 2023 Share Posted May 13, 2023 If you’re going to do splits etc with a Henley then put a 100A isolator in as well and terminate the SWA at that - will mean you can isolate the boards and also make it a bit safer to work on Link to comment Share on other sites More sharing options...
TonyT Posted May 13, 2023 Share Posted May 13, 2023 1 hour ago, PeterW said: If you’re going to do splits etc with a Henley then put a 100A isolator in as well and terminate the SWA at that - will mean you can isolate the boards and also make it a bit safer to work on There should be one at the other end of the Swa Link to comment Share on other sites More sharing options...
TonyT Posted May 13, 2023 Share Posted May 13, 2023 1 hour ago, connick159 said: Yeah, thinking of splitting the armoured via one of those junction boxes (Henley block) I think they are also called. One.eqch for the N and L feeds and then sending one to top CU and then other to bottom CU. Then the rest as you say sorting out the config of circuits in the top CU and RCD (or RCCB) in the bottom. Thanks again all. Remember the armour cable needs to be glanded into a metal box. the single insulated cables of the armour can’t leave the box/cu. Only double insulated such as meter tails can do this Link to comment Share on other sites More sharing options...
PeterW Posted May 13, 2023 Share Posted May 13, 2023 36 minutes ago, TonyT said: There should be one at the other end of the Swa agree however he’s relying on splitting the boxes and 2 isolators in the CU’s, and tbh for the £20 for a 100A metal clad isolator it is a bit of a no brainer - can also protect the split on the tails too. Personally I would rip the lot and put a double decker board in and start again … Link to comment Share on other sites More sharing options...
Jenki Posted May 13, 2023 Share Posted May 13, 2023 On 12/05/2023 at 20:01, TonyT said: There's also the issue that MCBs tend not to discriminate with MCBs generally it's a bad idea to feed an Consumer Unit from an MCB in another Consumer Unit Probably at least 70% of houses that have a shed/ garage CU have this arrangement. Link to comment Share on other sites More sharing options...
TonyT Posted May 13, 2023 Share Posted May 13, 2023 6 minutes ago, Jenki said: Probably at least 70% of houses that have a shed/ garage CU have this arrangement. Maybe so, but it’s not good design. Link to comment Share on other sites More sharing options...
connick159 Posted May 14, 2023 Author Share Posted May 14, 2023 (edited) What's the requirements for surge protectors? Mine do not have any but I've seen them on Hager website and now unsure if they are required by regs? If so, and each cu gets separate feeds as per the Henley block suggestions, would I need 1 in each cu? Edited May 14, 2023 by connick159 Link to comment Share on other sites More sharing options...
TonyT Posted May 14, 2023 Share Posted May 14, 2023 18th edition do require this The spd clips to the din rail like an mcb it should be next to the main switch and will protect the whole installation Link to comment Share on other sites More sharing options...
connick159 Posted May 15, 2023 Author Share Posted May 15, 2023 Hi all, Just updating. New sparks came in today. Ripped it out and started again. Also added a new isolation switch and SPD on the feed into the armoured cable near the meter coming in. Back tomorrow to finish off. Thanks again for all the advice. Been a £1100 lesson but I appreciate all the feedback from you all. Cheers. 4 Link to comment Share on other sites More sharing options...
ProDave Posted May 15, 2023 Share Posted May 15, 2023 That's looking better. So he opted for a new CU rather than reconfigure what was there? Neat job. Do i take it all the circuits so far have tested okay or has he found any faults? Look forward to the finished photos. Link to comment Share on other sites More sharing options...
connick159 Posted May 15, 2023 Author Share Posted May 15, 2023 (edited) 5 minutes ago, ProDave said: That's looking better. So he opted for a new CU rather than reconfigure what was there? Neat job. Do i take it all the circuits so far have tested okay or has he found any faults? Look forward to the finished photos. They went and got new gear and started fresh. A lot of the day was spent ripping out, reading the notes and labels from other guy but also doing work on the incoming feed. I wasn't there except to let them in but I think, apart from some preliminary testing earlier today, most of their testing is in for tomorrow. But he did say that there are a lot of junction boxes been used up in the attic/ceiling which they thought unnecessary. Some of which still seem to need completing so unlikely he'll be able to sign everything off by cob tomorrow. Edited May 15, 2023 by connick159 Link to comment Share on other sites More sharing options...
Carrerahill Posted May 15, 2023 Share Posted May 15, 2023 1 hour ago, connick159 said: Hi all, Just updating. New sparks came in today. Ripped it out and started again. Also added a new isolation switch and SPD on the feed into the armoured cable near the meter coming in. Back tomorrow to finish off. Thanks again for all the advice. Been a £1100 lesson but I appreciate all the feedback from you all. Cheers. This guy knows what he is doing and takes pride in his work. Link to comment Share on other sites More sharing options...
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