Electrician Required - Regs/CU question

Makhaira

Makhaira

Makhaira

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23 Nov 2007
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Lancashire, UK
My house was built in 1996, and as far as I'm aware, has no electrical issues. I realise that regs are always changing, but I know now and again there are more significant changes.

Currently I have a CU with RCD's stamped to BS3871, a main CB with 30mA rating stamped to BS4293, and the CU itself is stamped BS5486 Pt 13 all of which I understand has been superseded. Now obviously I don't want to shell out a packet of cash for something that already works fine, but if anything major has changed, I'd like to keep up to date given a fair amount of technology in the house, and workshop machinery in the garage.

I'm just looking to move on from "critical" jobs in the house and more on to jobs to make things "just so".

The question is - does this need changing, or shall I just stick with this until such time as I need more circuits? My understanding is that the 30mA change was the most critical, which I have. With them just being RCD's I guess I don't have any overcurrent protection, but I think this is still the case unless I was to fork out a lot of money for RCBO's?

Cheers.
 
Nothing wrong with it, will last another 30 years or so, before house needs rewiring.
I presume 30mA RCD protects just ring mains.

Just had a quick look at the regs here, BS3871 was replace by BSEN60898 in the 90's, you can't used them in a new installation, but you still you them in an existing installation.
 
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Pics please...Speaks a thousand words etc

From 1996 to now, chances are the regs would recommend some kind of upgrade, cant tell until ive seen a pic though.

You probably have either 2 situations going on, either not all the circuits are protected by the rcd, or they all are protected by the same rcd.

Both not upto current regs, first for safery, 2nd for inconvenience.

You have over current protection provided by the fuses, earth fault protection by the RCD, you should never have a situation with no over current protection.

Also your earthing and bonding may not be upto current regs, which say you should have 16mm earth and 10mm bonding to the gas/water/oil supply where they enter the property, so normally, water at the main stopcock, gas on the right hand side of the meter.

The size of the main earth and bonding doesn't really matter too much, bonding as long as it is there even if its say 6mm.

Regs recommend the elecs are inspected at a minimum of every 10 years for domestic installations, so you could get an inspection done, EICR, electrical installation condition report, which would mean someone testing everything and producing a list of upgrades required, splits into 1 dangerous fix now, 2 potentially dangerous fix asap and 3 not upto current regs, advise to get fixed.

The downside to this is it costs money and you just get a piece of paper, no work done etc, but its provides a good starting point to plan work from.

Also RCDs are supposed to be tested quarterly by pressing the test button, if they RCD doesn't trip, then you should get a spark to take a look, if the RCD is over a certain age you might not be able to replace just the RCD and it might need the whole CU changed.
 
IF you get a new CU you can get 2 types, cheaper dual RCD 17th or a full RCBO board

NOTE, you cannot use an RCBO board if you have a tt earthing system, spark should check this.

Dual RCD is just that Half circuits on 1 RCD 2nd half or circuits on the 2nd RCD, cheaper option, can be inconvenient as when the RCD trip you loose half the house.

Full RCBO board, each RCBO has over current and earth fault protection built it. So each circuit is independent and will trip individually not affecting the others, costs a fair but more but less potential for trouble, and the cost spead over the next x number of years might be worth it.

PS. Any idea on the age of the wiring itself?? is the 1996 you said in the OP just the age of the current fuse box and the wiring could be much older??
 
HardwareGeek said:
Pics please...Speaks a thousand words etc
+1

Regs recommend the elecs are inspected at a minimum of every 10 years for domestic installations.
Click to expand...

I know places were they haven't been inspected in 25 years.:eek:

When I moved to present place, I replace the CU which had a mixture of rcd's & cartridge fuses , with a split load CU, house will be rewired this year.:)
 
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Looks like most of the CUs in the country, probably the most common setup, RCD protects the circuits on the left only, no protection for your lights and cooker, smoke alarms arguably shouldn't be RCD protected anyways, thats up for debate tbh

So overall nothing to worry too much about, just the lights and cooker dont have RCD protection.

Those MEM RCDs trip half way, so push down then up to reset but i guess you know that already.
 
Thanks HardwareGeek. I'll stick with it as it is then for the time being (only came to mind as I had to dismantle a 3 loop lighting connection from within a light fitting, junction box it in the loft - bloody hard to get 5 cables into a junction box! - to fit a bathroom light).

Am I going to hit regs issues when I fit a new kitchen and get a new oven?

Really appreciate the advice guys, thanks.
 
HardwareGeek said:
No protection for your lights and cooker, smoke alarms arguably shouldn't be RCD protected anyways, that's up for debate tbh.
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Now that is a interesting point you raise there, I would have the cooker protected, certainly wouldn't protect smoke alarm or lights.

Many years ago I broke my arm falling down the stairs in a house, because some sparky had the lights circuits on a rcd & it tripped.:(
 
The kit sockets should be ok, RCD protected etc.

Cooker might be problematic, afaik if you pay for installation by the store, they wont connect the cooker unless its RCD protected, But then you could do the connection yourself.
 
Nightglow said:
Now that is a interesting point you raise there, I would have the cooker protected, certainly wouldn't protect smoke alarm or lights.

Many years ago I broke my arm falling down the stairs in a house, because some sparky had the lights circuits on a rcd & it tripped.:(
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I would say if the smokes are on there own circuit then probably no RCD protection. Might alter them to run off the lights?

But if linked into the downstairs lights, so you can tell if they have tripped, then RCD protection.

Default in the regs now is to RCD protect everything unless there is a good reason not to.

Avoiding your accident, depends on what caused it, if it shared an RCD with other circuits, sockets etc, then chances are the sockets tripped the RCD and took the lights out aswell, RCBO board would solve that.

Lights could always trip from a blown bulb etc, not so easy to avoid, could try a type c / d MCB / RCBO to avoid trips as much as possible.
 
Nightglow said:
Done a few jobs where the owner has actually requested a seperate ring main covering kitchen & utility room.:eek:
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Thats pretty common as the kitchen probably uses 90% of the power in the house if you dont count the shower etc.

Not a bad idea.

Latest thing in posh places is separate 16/20A circuits for each appliance in the kitchen aswell as separate counter top sockets.
 
HardwareGeek said:
I would say if the smokes are on there own circuit then probably no RCD protection. Might alter them to run off the lights?

But if linked into the downstairs lights, so you can tell if they have tripped, then RCD protection.

Default in the regs now is to RCD protect everything unless there is a good reason not to.

Avoiding your accident, depends on what caused it, if it shared an RCD with other circuits, sockets etc, then chances are the sockets tripped the RCD and took the lights out aswell, RCBO board would solve that.

Lights could always trip from a blown bulb etc, not so easy to avoid, could try a type c / d MCB / RCBO to avoid trips as much as possible.
Click to expand...

If it had been my place, I probably would have tried d MCB's or the RCBO.
I only do electrics on my place now, & I must admit I haven't kept up to date with the regs.:o

Having a clear out last week, & I found all C&G Electrical city and guilds 236 "c" course work i did at college from 30 years ago, how things have changed.:eek:
 
Only did my regs approx 2 years ago, forgotten a lot already, only remember the day to day stuff after awhile.

Afaik the exams are designed that way, they expect you to just look up anything rather than remember any of it.
 
Nightglow said:
Done a few jobs where the owner has actually requested a seperate ring main covering kitchen & utility room.:eek:
Click to expand...

That's how I did mine when we put in a new CU and removed the terrible wiring from the kitchen. Diagonal wires covered in (just) tiles, T&E hanging underneath the cupboards that turned out to be part of the ring. My wife had an absolute fit when we uncovered it all (she's in the electrical testing & safety industry).

So we put in a new ring just for the kitchen & ute, and a dedicated non-RCD radial for the fridge freezer. Might not stand up to current regs but it was fine at the time :)
 
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