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it seems that post re-wire, that at least part of the downstairs wiring is on the sockets circuits. There is an additional switch in the understairs cupboard that controls the lighting loads. This all leads back to a new board. 

 

Is is it acceptable to mix sockets and lighting? Is there any good reason for doing so? I suspect it’s down to making a temporary circuit to get a room powered up. 

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"it seems that post re-wire, that at least part of the downstairs wiring is on the sockets circuits"

 

Do you mean downstairs LIGHTS wiring is on the sockets circuits?

 

"additional switch

 

Do you mean a circuit breaker? 

 

Maybe it's been done as a temporary thing. Sometimes a feed for lighting is taken off the ring or radial but usually fused down accordingly.

 

Circuits should be segregated accordingly say if using a split load board with two RCDs. So Downstairs Sockets on RCD1, Downstairs Lights on RCD2. In the event of any circuit trippping one of the RCDs you can still plug in a lead light etc or run an extension for something like a freezer whilst you fix the other side. This is why also all RCBO is best.

 

 

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Lights on sockets circuit, with a switched fuse to take it down for the lighting circuit. 

We have 2 RCD’s and twelve individual loads in two lots of 6. 

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Posted (edited)

It's not ideal, but it's not terrible. Generally done for a single light fitting such as a porch or cupboard or for a small extension such as a conservatory. It would be unusual to plan for a significant part of the main installation to be configured in that way. But re-wires are often compromises if some parts of the house structure are inaccessible due to laminate flooring or other permanent finishes.  I'd normally expect to discuss potential issues like this with clients at the planning stage ... so design decisions are are jointly planned. What does your electrician say?

Edited by Dee J

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1 hour ago, Lesgrandepotato said:

Lights on sockets circuit, with a switched fuse to take it down for the lighting circuit. 

We have 2 RCD’s and twelve individual loads in two lots of 6. 

 

It's good practice to leave a couple of spare ways in the consumer unit. Wondering if your board was big enough in the first place. I and most would put the lights on their own breaker.

 

Fused spurs are permissible but it's going to be a bit impractical if the say downstairs lights are fed from a fused spur off the downstairs ring. If the RCD goes you lose lights AND power. If you get my drift? If the fused spur is say 5A then an over current or short circuit on the lights should just take out the 5A fuse and not affect the "sockets" circuit it's fed from. However if either circuit has an earth leakage fault the RCD will trip losing power to both.

 

The BS is pretty specific about one circuit going out not affecting another. Though a split board is always going to be a compromise on that, careful arrangement with regards to up not affecting down minimises the issue. Of course the BS isn't law! 

 

Money no object you could likely ditch the two RCDs / breakers and clip a line of RCBOs to the DIN rail. It has been done, retaining the same cu.

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I'll admit to having done it, when I cocked up and forgot to run the upstairs lighting ring to the two eaves spaces what we have as storage areas.  Luckily both had easy rear access to the upstairs ring final, so all I did was fit a switched FCU, with a 3 A fuse, wired with a short 2.5mm² spur from the back of one of the DG outlets, as the light switch in each of them, with a label stuck on saying that the fuse should be 3 A.  It's legal, and perfectly OK, if not best practice, but sometimes you just have to take the easy way out.  I wasn't going to take the bonded down bamboo flooring up to get access to the upstairs lighting ring!

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As others have said, it's technically okay but not perfect. I would not expect it on a "rewire"  I sometimes do similar things when doing alterations if it can save a lot of work or trashing the decor, but I always discuss the options and pros and cons with the customer.

 

Sadly yet another example of the generally poor work you have had done.

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6 minutes ago, ProDave said:

 

Sadly yet another example of the generally poor work you have had done.

 

Care to add to that comment? Not sure I follow? 

 

So as I see it, it is viable. It’s not ideal and should not have been put in this way. 

 

I’ll speak to the sparks about rectifying it to get is as it should be. 

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3 minutes ago, Lesgrandepotato said:

 

Care to add to that comment? Not sure I follow? 

 

So as I see it, it is viable. It’s not ideal and should not have been put in this way. 

 

I’ll speak to the sparks about rectifying it to get is as it should be. 

I might be getting confused with members but were you not the one having lots of issues with the build?  I could be confused after driving 11 hours today.

 

Yes it's technically okay but not what I would expect if you were having a "rewire"

 

 

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2 minutes ago, Lesgrandepotato said:

 

Care to add to that comment? Not sure I follow? 

 

So as I see it, it is viable. It’s not ideal and should not have been put in this way. 

 

I’ll speak to the sparks about rectifying it to get is as it should be. 

 

The consensus is it seems a bit of a bodge in the face of how most would approach it but not unsafe. It may be inconvenient if both trip. The fuse blows, the first thought is to go to the cu not the fused connection unit. Might not be someone who knows what's been done and where things are. 

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Posted (edited)

I'm not touting the SBS products but a couple of pics of a pre assembled line of DP RCBOs done for a customer with an existing cu - in this instance Wylex. The idea as I alluded to above is out with the old main switch, RCDs and breakers. For every 2-module wide RCD you ditch you get space for two more circuits. In a split load board thats 4 more ways. Each circuit is protected by its own RCBO and if it trips it affects no other circuit. Clips onto the existing DIN rail. Tails into the main switch, line and neutral for each circuit into the L & N atop each RCBO and all cpcs (earths) to the earth bar of the cu.

 

Note the separate L & N bars running under the line of RCBOs - means you don't have a neutral bar on the enclosure like on most.

 

57330f845a131_CompactRCBOMainSwitchAssembly1.thumb.jpg.60de48d8a8b5b692bde0f42f3b39bec5.jpg.15964c8cb42452e23a0b4c6dd4024e5d.jpg

 

57330f9463ec4_CompactRCBOMainSwitchAssembly2.thumb.jpg.b3b2c24b737c95ba089a4ceea8d303ea.jpg.75ee424029a17d7d3ceb1f0cd7c2f1d4.jpg

Edited by Onoff

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4 hours ago, Onoff said:

 

The consensus is it seems a bit of a bodge in the face of how most would approach it but not unsafe. It may be inconvenient if both trip. The fuse blows, the first thought is to go to the cu not the fused connection unit. Might not be someone who knows what's been done and where things are. 

Fixed wiring terminates at the fused spur anyway, so it matters not one jot what is connected, as long as it's safe. 

For a new rewire I'd be less than happy, unless, as stated above, it's been by prior approval between yourself and the sparky and you were made aware of the compromise before it was undertaken.

As you have stated its the majority of the floors lighting that's affected, I'd ask immediately for it to be rectified without charge. It's not acceptable IMO, and I'd be just ok if it was a partial rewire. 

Get it changed and get the amendment notified in the certification. ;)

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Posted (edited)

Comes down to this will become a "leave as is / not worth the hassle" when you don't have a spare way in the cu to run a dedicated circuit or to do so will mean such disruption to finishes as alluded to above to run the cable with ripping up floors etc. Might be a live 'n learn! Maybe you could shame the sparks into giving you a few quid of his bill for the aggravation if you can live with it. Remember, the day (night? :( ) you have an earth fault on those sockets the lights are going off!

 

Edit: The sparks might try and suggest (it might be the case) that it was some material change you made to an agreed spec, like adding circuits meant there were no spare ways left in the cu but he still should have advised.

 

Remember PPPPPP! :)

Edited by Onoff

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Why not fit one light as emergency lighting with a backup battery then if the power goes off you still have light for a bit while you fumble for s torch.

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10 hours ago, Onoff said:

I'm not touting the SBS products but a couple of pics of a pre assembled line of DP RCBOs done for a customer with an existing cu - in this instance Wylex. The idea as I alluded to above is out with the old main switch, RCDs and breakers. For every 2-module wide RCD you ditch you get space for two more circuits. In a split load board thats 4 more ways. Each circuit is protected by its own RCBO and if it trips it affects no other circuit. Clips onto the existing DIN rail. Tails into the main switch, line and neutral for each circuit into the L & N atop each RCBO and all cpcs (earths) to the earth bar of the cu.

 

Note the separate L & N bars running under the line of RCBOs - means you don't have a neutral bar on the enclosure like on most.

 

57330f845a131_CompactRCBOMainSwitchAssembly1.thumb.jpg.60de48d8a8b5b692bde0f42f3b39bec5.jpg.15964c8cb42452e23a0b4c6dd4024e5d.jpg

 

57330f9463ec4_CompactRCBOMainSwitchAssembly2.thumb.jpg.b3b2c24b737c95ba089a4ceea8d303ea.jpg.75ee424029a17d7d3ceb1f0cd7c2f1d4.jpg

That looks like a nice piece of kit. Single module double pole rcbos like this are fairly standard in France , but rarely seen in the UK. What's your preferred source for these parts? And how do you get round the various regs glitches when fitting them into pre-existing consumer units from other manufacturers? Such as approvals of boxes only apply when fitted with the box suppliers own components (especially when connected to the DNO supply direct) or the updated requirements on non-combustible enclosures? No criticism intended, just need to know how to present an install like this to my scheme assessor.

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16 minutes ago, Dee J said:

That looks like a nice piece of kit. Single module double pole rcbos like this are fairly standard in France , but rarely seen in the UK. What's your preferred source for these parts? And how do you get round the various regs glitches when fitting them into pre-existing consumer units from other manufacturers? Such as approvals of boxes only apply when fitted with the box suppliers own components (especially when connected to the DNO supply direct) or the updated requirements on non-combustible enclosures? No criticism intended, just need to know how to present an install like this to my scheme assessor.

Simple answer is BS7671 is not "the law" just one way to comply with it.  There has to be a bit of common sense. e.g a Crabtree rcbo would be no more or less likely to catch fire in a wylex box than a crabtree box.

 

Those components are sold in the UK by a trade only distributor. To make up an all rcbo set up like that costs roughly double the price of a standard split load twin rcd setup, and for me unfortunately most of my customers I have offered that to reject the cost and opt for the standard twin rcd split load board.

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53 minutes ago, Dee J said:

That looks like a nice piece of kit. Single module double pole rcbos like this are fairly standard in France , but rarely seen in the UK. What's your preferred source for these parts? And how do you get round the various regs glitches when fitting them into pre-existing consumer units from other manufacturers? Such as approvals of boxes only apply when fitted with the box suppliers own components (especially when connected to the DNO supply direct) or the updated requirements on non-combustible enclosures? No criticism intended, just need to know how to present an install like this to my scheme assessor.

 

So many points there! :) Tbh I can't answer them all, only really generalise.

 

See here for the SBS page ref certification:

 

https://www.sbstradesales.co.uk/products/

 

Somebody else on here recently went all DP RCBO but not from SBS as SBS sell to trade only. They went to Live Electrical for their stuff. I think the Live and SBS DP RCBO's are all made in the same factory. Live have strong Chinese links as in company directors:

 

https://beta.companieshouse.gov.uk/company/07429017/officers

 

There's some tie up as SBS use Live boards.

 

My take on the mix 'n match is that individual components like the metal enclosure and a line of like RCBOs even if from different makers, when put together, combine to satisfy the regs. Most problems are caused IMO when people fit / force in the physically wrong sized breaker with different busbar offsets. Don't know what an insurance company would make of it in the event of an issue...

 

When a split load board of any make simply doesn't comply with the regs anyway I'd see such an upgrade as making an old board more compliant rather than less. We all know split load boards are a compromise. 

 

That's all I've got! 

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My key mantra is leave it safer than it was before I started. Sometimes it may not be perfect but a hell of a lot better than it was.

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My house will be an all RCBO (stand fast fire alarms and fridge/freezer circuit), but it is over the top specified 16 way 3-phase board (which gave me spare capacity) and i think the electrician said he was going to install a 24 way board anyway, so I will have the space/capacity to do whatever we require.

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+1 to that. Great not having the PC die just because the hob ignition or toaster element failed.

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