Electrical question

[Masood]

I know some of you esteemed gentlemen occasionally dip into the cesspool that is electrickery so before sullying myself by visiting the sparky forum I'll ask here...

We're refurbishing our rental flat and the electrics are "interesting".

Economy 7 (we want rid of it)
All sockets on one ring (whole property under 100m2)
One circuit for storage heaters (removed a long while ago)
Immersion on it's own fuse
Shower and cooker on one fuse (well over it's capacity)

We are getting rid of fuse board, replacing with modern consumer unit.
Shower getting it's own RCBO
Oven getting it's own RCBO
Hob getting a new spur directly off consumer unit, it's own RCBO
Two new spurs off separate RCBOs for space heaters in bedroom and living room
Various sockets being relocated

We've been told that if we do major works such as a rewire (or have an extension built etc) then the kitchen MUST be on a separate ring to comply with regs.

My question is - does the above count as a rewire? Obviously it's not a full rewire but in my opinion it's a major enough piece of work to count as such and therefore need to comply. SWMBO (degree in electrical engineering) disagrees. no dispute that it's good practice to have a separate ring, but is it obligatory?

I have in mind Part L, and how a number of "component upgrades" ***ulatively become classed as a "system upgrade", necessitating fuller compliance. But I don't know if this applies to electrics as it does to gas & heating...

TIA,
Masood

 

[Ermintrude]

Yes mate . Why all the rcbo? U can get a fully loaded 17th ed board from poo sticks for £80

 

[GasmanxxxR1]

Agree with ermi why rcbo

 

[GasmanxxxR1]

If your repalcing stuff but not altering the circuit then its not a rewire and must be left no worse than it was before

 

[kris]

Hi masood. Defo some bad electrics stated there especially cooker n shower on same fuse, plus only 1 ring main , so remember kitchen totally seperate , but what youl probably find is junction box city hiding behind walls if your doing any tear downs so prob best to re wire or get circuits tested but youl just get told what you already know its just a case of knowing how far to go, good luck

 

[Reg Man]

Any new works must comply with current 17th edition, so RCBO's are not a bad option. Most people go for a split board with RCD's. In any event you will require a full Electrical Works Certificate and Part P building Regulations Certificate to say that the new works comply. Any pre existing electrics must be safe, but may not satisfy current regulations.

 

[Masood]

Thanks all. I'm in favour of a full rewire for safety's sake. The place is gutted at the moment so seems like the best time. Mrs B was hoping to get it done and dusted a bit quicker than it will take.

Why RCBOs? I asked the same question - seems overkill to me. But SWMBO insists and to be fair, although more expensive they are a better product. Although we're renting it out for now, we're planning on living here eventually so not too worried about cost...

 

[Toxic Ted]

Yes mate . Why all the rcbo? U can get a fully loaded 17th ed board from poo sticks for £80

"Poo sticks"....i've just spilled me tea down a clean tee shirt you git.

 

[Reg Man]

RCBO's Are a combined RCD and MCB, so if you use them you don't have to faff around arranging your circuits on a split board. ie: upstairs lighting circuit on different split to down stairs circuit.

 

[solutions]

RCBO's Are a combined RCD and MCB, so if you use them you don't have to faff around arranging your circuits on a split board. ie: upstairs lighting circuit on different split to down stairs circuit.

And a duff circuit or appliance on a circuit thats tripping will be easier to pin down quickly. I would have rcbos over split board any day despite extra cost.

 

[bacon_sandwich]

I would always wire a kitchen on its own ring and for a small place, another ring for the rest. The reason is that rings rely on evenly distributed loads. Worst case is that the CU is in the kitchen, if you wire just one ring then nearly all the load from the kitchen will go down just one leg of the ring and put the cable under stress. RCBOs from British General are only about 15 squid. They have benefits as mentioned above plus some properties have very leaky equipment (read electronic) so having more RCDs spreads the leaky loads across more 30mA RCBOs and as such reduces nuisance tripping.

 

[Reg Man]

Common ones are earth leakage on freezers. Always want to challenge RCD's

 

[Ermintrude]

Had a few rcbo a melt open after a cable spike. But earth leaks should ideals be rectified . Nice Merlin board fully populated with RCBOs will set u back about £200

 

[bacon_sandwich]

Common ones are earth leakage on freezers. Always want to challenge RCD's

Went to a flat with 4 A/C units, even on standby they leaked 3.5mA a piece. eek, They went on RCBOs . lol

 

[Best]

I spoke about this thread to a friend who is an electronic engineer & a top engineer at that & coincidently is about to do new wiring system for his own place.
His take on all this, (& I have removed some of the expletives he made about plumbers & most sparks) was this in an email to me -

"Re RCBOs - as the name suggests, they are a MCB with integral RCD! Good but unnecessary and expensive! A typical MCB is a couple of quid but these are £15-20 each. Not needed if an RCD feeding consumer unit. Only advantage is that if you have a dodgy appliance with earth leakage etc, it will only take down that circuit. Not a fat lot of use if your main ring main etc as you need to find the culprit or you can't get circuit back on until fault removed. Does mean, however, that your lights etc are still on for you to see!!!!
There are idiots who put these on where they have frequent tripping in order to not impact the remainder of house and other idiots talking about leaky appliances and sharing the leakage across a number of RCBOs in order to reduce tripping ( assuming leaky equipment on various circuits). If there is a small electrical leakage in your immersion e.g. It does not mean that it is an old element and acceptable and should be managed better by RCBOs ... It means it needs replaced! Same rules with other (typical element and or water based elements) steam irons, cooker elements (leaking moisture from cooking or elements starting to break down. "

He also later added - " FIX the leakage problem, don't try and resolve by electrical workarounds to minimise or hide the problem!! No leakage is acceptable - after all, how does virtually every household do without any trips?

 

[Masood]

I spoke about this thread to a friend who is an electronic engineer & a top engineer at that & coincidently is about to do new wiring system for his own place.
His take on all this, (& I have removed some of the expletives he made about plumbers & most sparks) was this in an email to me -

"Re RCBOs - as the name suggests, they are a MCB with integral RCD! Good but unnecessary and expensive! A typical MCB is a couple of quid but these are £15-20 each. Not needed if an RCD feeding consumer unit. Only advantage is that if you have a dodgy appliance with earth leakage etc, it will only take down that circuit. Not a fat lot of use if your main ring main etc as you need to find the culprit or you can't get circuit back on until fault removed. Does mean, however, that your lights etc are still on for you to see!!!!
There are idiots who put these on where they have frequent tripping in order to not impact the remainder of house and other idiots talking about leaky appliances and sharing the leakage across a number of RCBOs in order to reduce tripping ( assuming leaky equipment on various circuits). If there is a small electrical leakage in your immersion e.g. It does not mean that it is an old element and acceptable and should be managed better by RCBOs ... It means it needs replaced! Same rules with other (typical element and or water based elements) steam irons, cooker elements (leaking moisture from cooking or elements starting to break down. "

He also later added - " FIX the leakage problem, don't try and resolve by electrical workarounds to minimise or hide the problem!! No leakage is acceptable - after all, how does virtually every household do without any trips?

It is precisely because they will only take out one ring that we are installing them. We live in London, the property is in Leicestershire. One single callout to a local sparkie in an emergency would pay for half the total RCBOs required. And if the kitchen ring blows, the rest of the flat including shower, hot water cylinder, lights etc are all still available. We do actually care about our tenants and want to minimise inconvenience. A bit more capital outlay whilst doing a total gut-out and refurb seems worthwhile.

As for expletives about plumbers, well, he's entitled to his view but my take is that I'm fully aware of my limits but have no qualms about chasing out cable runs and wall boxes, running cables then getting a qualified spark in to connect the the CU. And I'm asking for advice before doing anything at all.

 

[solutions]

I spoke about this thread to a friend who is an electronic engineer & a top engineer at that & coincidently is about to do new wiring system for his own place.
His take on all this, (& I have removed some of the expletives he made about plumbers & most sparks) was this in an email to me -

"Re RCBOs - as the name suggests, they are a MCB with integral RCD! Good but unnecessary and expensive! A typical MCB is a couple of quid but these are £15-20 each. Not needed if an RCD feeding consumer unit. Only advantage is that if you have a dodgy appliance with earth leakage etc, it will only take down that circuit. Not a fat lot of use if your main ring main etc as you need to find the culprit or you can't get circuit back on until fault removed. Does mean, however, that your lights etc are still on for you to see!!!!
There are idiots who put these on where they have frequent tripping in order to not impact the remainder of house and other idiots talking about leaky appliances and sharing the leakage across a number of RCBOs in order to reduce tripping ( assuming leaky equipment on various circuits). If there is a small electrical leakage in your immersion e.g. It does not mean that it is an old element and acceptable and should be managed better by RCBOs ... It means it needs replaced! Same rules with other (typical element and or water based elements) steam irons, cooker elements (leaking moisture from cooking or elements starting to break down. "

He also later added - " FIX the leakage problem, don't try and resolve by electrical workarounds to minimise or hide the problem!! No leakage is acceptable - after all, how does virtually every household do without any trips?

I dont think that anyone on here said mcbos should be used to avoid correcting electrical faults just that the single benefit as your engineer friend referred to it as, was worth having despite the increased cost.

 

[Best]

I had just put his point of view out there as he has great knowledge on the subject & is coincidently about to do similar work at his home. I thought his comments were worth listening to. He is a top bloke IMO, who always thinks everything out really well & has often fixed lots of electrical/electronic or mechanical items for me & gives me advice. Never seen him be wrong, ever & usually very quick at diagnosing faults - even telling me what is wrong with gas boilers that others can't fix at all.
His remarks about plumbers & "most sparks" is partly well meaning banter with him, but he does have a point that most plumbers generally speaking have limited basic knowledge of electrics & many but not all sparks are wire fitters & not necessarily well trained.

I think it was the comment about spreading the leaks using RCBOS that he disagreed mostly with & I guess he has a point - any slight faults are better to show themselves & be fixed.
For rental property, I understand doing it so power will remain to rest of place & avoiding call outs - especially after hours! I for example recommend Tigerloops be fitted on all oil boilers on rentals so there's no phone calls for call outs from tenants when they run out of oil, - which with some idiots is frequent.
I think split load which uses a couple of RCBs & then individual MCBs, if split correctly would do most private properties spot on & should keep kitchen & each ring mains & each lighting circuits separated.
This would surely be more than enough for a brand new properly wired or rewire, as the only likely faults in the future will be mostly with appliances, which should normally be easy to guess & find on each small circuit.

 

[Reg Man]

Partly agree with the above comments. Earth leakage on most equipment is not acceptable as it indicates faulty appliances. As for freezers and the like, they are inherently prone to earth leakage. The point is to design a system where nuisance tripping is avoided, not an excuse to circumvent doggy equipment. Hence RCBO's are not a bad option. Agree that a split board is a good option too, on a properly designed system.

 

[Ermintrude]

Split load 17th ed board and robo on kitchen? Don't forget each RCBO needs to be periodically tested and receive a periodic every 5 years .