epsilonGreedy Posted February 11, 2020 Share Posted February 11, 2020 I have fallen into a pit of consumer unit research this morning which was prompted by a need to instruct the brick layers where to position a recess in the wall to accommodate a unit. Now my mind is buzzing with issues, like split load CUs, dual bank, fully loaded units, mini switches, RCBOs, surge protection and 18th Edition. For a new build 3 bed house, 100amp single phase supply what should I ignore while selecting a unit? These options look interesting... https://www.consumerunitworld.co.uk/hager-vml118spd-18-way-main-switch-consumer-unit--surge-protection-3622-p.asp Fully loaded at a good price! https://www.consumerunitworld.co.uk/hager-vml916curk-16-way-high-integrity-fully-loaded-dual-100amp-rcd-metal-consumer-unit-3567-p.asp Link to comment Share on other sites More sharing options...
PeterW Posted February 11, 2020 Share Posted February 11, 2020 £35 cheaper https://www.screwfix.com/p/wylex-21-module-12-way-populated-high-integrity-dual-rcd-consumer-unit/9305p Link to comment Share on other sites More sharing options...
ProDave Posted February 11, 2020 Share Posted February 11, 2020 It's not that complicated. It obviously has to be compliant with the 18th edition, but you would be hard to find one that was not from a reputable supplier. The only real decision is split load, or rcbo. Split load generally has two rcd's. The disadvantage is a fault on one circuit could trip half your board. Rcbo's are more expensive but generally a fault on one circuit won't affect any others. The one Peter linked to earlier will be fine. Personally I am a fan of Hager but they are more expensive, mine is Hager all rcbo. The thing I like about Hager is they don't keep changing the design so a new Hager mcb will fit an old Hager consumer unit and still fit and still look right. You can't say the same for MK, Wylex etc. Link to comment Share on other sites More sharing options...
joth Posted February 11, 2020 Share Posted February 11, 2020 (edited) I predict at some point someone will suggest http://sbstradesales.co.uk Edited February 11, 2020 by joth Link to comment Share on other sites More sharing options...
ProDave Posted February 11, 2020 Share Posted February 11, 2020 1 hour ago, joth said: I predict at some point someone will suggest http://sbstradesales.co.uk Yes I have used him, but not many are prepared to pay the higher price. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 11, 2020 Share Posted February 11, 2020 I've bought some of these to try: https://www.electricalcomponentsdirect.co.uk/acatalog/Compact_Mini_RCBO_Circuit_Breakers.html First impressions are that they are extremely similar to the SBS ones and seem to be well made. Reasonably good value for DP compact RCBOs. I believe that ECD may do a metal board populated with these for a reasonable price. 1 Link to comment Share on other sites More sharing options...
epsilonGreedy Posted February 11, 2020 Author Share Posted February 11, 2020 1 hour ago, Jeremy Harris said: I've bought some of these to try: https://www.electricalcomponentsdirect.co.uk/acatalog/Compact_Mini_RCBO_Circuit_Breakers.html First impressions are that they are extremely similar to the SBS ones and seem to be well made. Reasonably good value for DP compact RCBOs. I believe that ECD may do a metal board populated with these for a reasonable price. Thanks I will bookmark that site. Looking at the individual RCBO prices at your link and then multiplying by 16 plus a basic case it makes the fully loaded units look like remarkable value. I must be overlooking something basic about the technical elements of a fuse box. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 11, 2020 Share Posted February 11, 2020 I have a suspicion that the populated RCBO boards that ECD sell probably use their SP RCBOs, rather than the DP ones. ECD don't seem to sell the staggered DP busbars, either, although SBS do, I believe. Link to comment Share on other sites More sharing options...
Thedreamer Posted February 11, 2020 Share Posted February 11, 2020 4 hours ago, PeterW said: £35 cheaper https://www.screwfix.com/p/wylex-21-module-12-way-populated-high-integrity-dual-rcd-consumer-unit/9305p I purchased this a few weeks ago and one of the rcds was faulty. I'm surprised as Wylex appears to be reputable brand. Going to buy a separate rcd and screwfix are apparently going to give me a credit. Link to comment Share on other sites More sharing options...
ProDave Posted February 11, 2020 Share Posted February 11, 2020 1 hour ago, Thedreamer said: I purchased this a few weeks ago and one of the rcds was faulty. I'm surprised as Wylex appears to be reputable brand. Going to buy a separate rcd and screwfix are apparently going to give me a credit. You don't remember the mass recall several years ago then? Link to comment Share on other sites More sharing options...
epsilonGreedy Posted February 11, 2020 Author Share Posted February 11, 2020 2 hours ago, Jeremy Harris said: I have a suspicion that the populated RCBO boards that ECD sell probably use their SP RCBOs, rather than the DP ones. ECD don't seem to sell the staggered DP busbars, either, although SBS do, I believe. Ok I am learning as I go. SP just disconnects the live and meets regs whereas DP disconnects live and neutral for true circuit isolation safety. I also assume cheaper CUs just have a couple of RDCs protecting multiple circuits each and basic overload breakers on each circuit. Combining the RCD and overload protection into each breaker means it is less likely the whole house will plunge into darkness when single light bulb or gas hob ignition fails and causes a residual wobble. Link to comment Share on other sites More sharing options...
Thedreamer Posted February 11, 2020 Share Posted February 11, 2020 3 minutes ago, ProDave said: You don't remember the mass recall several years ago then? Truth be told I didn't even understand what a consumer unit did until a few weeks ago. We have one here and never had a problem. They seem to me to be a long standing manufacturer of these units. Link to comment Share on other sites More sharing options...
Jeremy Harris Posted February 11, 2020 Share Posted February 11, 2020 8 minutes ago, epsilonGreedy said: Ok I am learning as I go. SP just disconnects the live and meets regs whereas DP disconnects live and neutral for true circuit isolation safety. I also assume cheaper CUs just have a couple of RDCs protecting multiple circuits each and basic overload breakers on each circuit. Combining the RCD and overload protection into each breaker means it is less likely the whole house will plunge into darkness when single light bulb or gas hob ignition fails and causes a residual wobble. Yes, a DP disconnects both L and N. The advantage of this, for an all RCBO board, is that it is safer, as it provides protection if there is an E - N fault. A split board with two DP RCDs and MCBs for each circuit (which is the minimum required by the regs) provides DP earth fault protection for all circuits, but does mean that any such fault takes out half the circuits in the house. An all SP RCBO board is OK, and means that an earth fault only takes out the affected circuit, but it doesn't necessarily provide protection against all faults; an E - N fault might not be be reliably detected. An all RCBO board, with DP RCBOs, provides protection against pretty much any fault condition, and also means that only the faulty circuit will trip, leaving all the others working. 1 Link to comment Share on other sites More sharing options...
MJNewton Posted February 11, 2020 Share Posted February 11, 2020 6 hours ago, ProDave said: The only real decision is split load, or rcbo. Or a combination of the two... Link to comment Share on other sites More sharing options...
epsilonGreedy Posted February 16, 2020 Author Share Posted February 16, 2020 On 11/02/2020 at 19:38, Jeremy Harris said: An all RCBO board, with DP RCBOs, provides protection against pretty much any fault condition, and also means that only the faulty circuit will trip, leaving all the others working. Ok a week later and a bit more knowledgeable on this subject I have been looking at the price of these options. There seems to be a £20 difference between a single pole MCB and single pole RCBO. For a half decent design with 15 protected circuit outlets I make that an extra £320 for an all RCBO design. Are my sums correct? My last rental house had dicky electrics and the whole house often tripped out leaving us groping around for a torch so I can see the benefit of a dual RCD design with the lights split across each RCD/Rail. Link to comment Share on other sites More sharing options...
epsilonGreedy Posted February 16, 2020 Author Share Posted February 16, 2020 (edited) On 11/02/2020 at 20:35, MJNewton said: Or a combination of the two... Is this what they call a "high integrity" CU with 3 rails? I like the idea of say the lights, freezer and security on RCBOs and the rest of the circuits controlled by communal master RCDs plus cheaper MCBs. This is a useful link for beginners trying to get their head around CU options. https://www.consumerunitworld.co.uk/choosing-a-consumer-unit-343-c.asp Edit: Another link with extra detail on high integrity CUs aimed at beginners. https://www.checkatrade.com/blog/2018/08/03/what-is-a-high-integrity-consumer-unit-and-when-should-it-be-used/ Edited February 17, 2020 by epsilonGreedy Link to comment Share on other sites More sharing options...
Nickfromwales Posted February 16, 2020 Share Posted February 16, 2020 7 minutes ago, epsilonGreedy said: Is this what they call a "high integrity" CU with 3 rails? I like the idea of say the lights, freezer and security on RCBOs and the rest of the circuits controlled by communal master RCDs plus cheaper MCBs. This is a useful link for beginners trying to get their head around CU options. https://www.consumerunitworld.co.uk/choosing-a-consumer-unit-343-c.asp That’s how I used to populate CU’s on my bread & butter work, eg where an all RCBO board wasn’t cost-effective enough for a client but they still wanted segregation. For me, it’s now ‘all RCBO’ or nowt. Just way too many plus points to consider going back to split / dual arrangement. Link to comment Share on other sites More sharing options...
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now