RCD's in Domestic Properties

[leep82]

Just wondering, all my training was done towards the 17th edition so i have always known/installed RCD's were necessary in domestic installations.

My mum has recently moved house and when i went round to have a look, i naturally gave the mains a glance. TNC-S supply and a split load board with 100A main switch and 80A 30ma RCD. On the RCD protected side there is kitchen and house ring main, cooker and shower, and off the main switch, lights and boiler supply.

Is this common of earlier editions of the regs? Ive heard of sockets needing RCD protection prior to 17th edition but what about the installation as a whole as there will obviously be cables buried at a depth of less than 50mm which arnt RCD protected.

The reason i ask is that the installation looks relatively new and there is even harmonised colour cable used ( although i suppose this could have been additional work carried out at a later date than original install ), surely somebody wouldnt have installed this to current regs?

 

[D Skelton]

Because you don't have a location containing a bath or a shower

You're missing the point

 

[leep82]

thanks i appreciate that, thats why i said ' where necessary'. Not having BGB at hand right now but under what circumstances would warrant an RCD not being required? Cables run/clipped direct to a surface or in containment system or buried at a depth greater than 50mm? Im not saying im right with those conditions may have misread/understood them.

Ah, I see. You missed the 'h' in 'where' in your original post. You can see where I'm coming from now

so i did, my apologies. Just trying to be a more active member on the forum. So any little scenarios i come across i like to get other peoples feedback/opinions on. Its a useful forum despite what ive read from other posters.

 

[telectrix]

so i did, my apologies. Just trying to be a more active member on the forum. So any little scenarios i come across i like to get other peoples feedback/opinions on. Its a useful forum despite what ive read from other posters.

yeah. just glance at reg. 522.6.101. applies to 17th, but was not required in 16th.

 

[jaypp]

Mostly what warrants it is (almost certainly) none was required on those circuits by the regs of the day it was installed. Like I say, I personally would lose no sleep over it, I don't lose any over living somewhere where the only RCD present is on the shower, but it's your call.

it's actually (i believe) the date of B.R approval which, so long as the build was started before planning approval ran out and B.R was approved at the same time, could be regs years older than the installation. awaiting abuse if wrong!!!!:redface:

 

[Sintra]

Completing a job in 2010 that was designed in 2008. This was all 16th edition signed sealed and delivered.

 

[trev]

I'm sure he is mate, I'm just trying to dispel the commonly held myth that just because it's a house it 'needs' RCDs in every situaton.

GASP! You mean.....they lie to us?
Surely the magic RCD will save us from all eventualities!
Damian, I think you're a heretic and should be burnt

 

[NickD]

Jeez, I thought he was scary enough before I found out his name was Damian. Where did I put those daggers...

 

[trev]

Damian's a ----- cat mate (as long as you know your stuff and don't challenge him without FULL facts) much the same as the rest of us really

 

[D Skelton]

A ----- cat indeed mate!

 

[trev]

Now I didn't say what kind of ----- cat mate

 

[Badged01]

...... Getting an Electrical Inspection Condition Report (EICR, formerly PIR) is recommended ...

eh...?

Now, now Glenn lets not get nit picky .... give the man some room to breath :smiley2:

 

[Adam W]

Sorry to muddy the waters but it doesn't comply with the current edition of BS7671 - additional protection by rcd should be recommended on an EICR.

That said I do agree that as long as it complies with 16th edition I wouldn't bother upgrading it just for the sake of it - it didn't suddenly become dangerous overnight.

 

[telectrix]

Sorry to muddy the waters but it doesn't comply with the current edition of BS7671 - additional protection by rcd should be recommended on an EICR.

That said I do agree that as long as it complies with 16th edition I wouldn't bother upgrading it just for the sake of it - it didn't suddenly become dangerous overnight.

only if the circuit cables on the non-RCD side don't comply with 522.6.101 in other ways. then it's a code C3.

 

[Badged01]

As so many of my learned colleagues have already correctly stated, RCD's are not required in domestic premises other than for specifically highlighted purposes within BS7671. However, as a generalism I think you can safely say most houses will have cable buried less than 50mm in walls, circuits in bathrooms and sockets likely to be used to power outdoor equipment!

If you were doing an inspection these would normally be C3 observations although two can become a C2 --- if following guidance from the electrical safety first publication!

In this example from the OP, with just lights/boiler being non-RCD protected then a C3 seems appropriate in not meeting current regs and an upgrade recommended --- unless the boiler feed is to a socket likely to be used for outdoors and there's no supp bonding in the bathroom!

 

[nickblake]

what should be considered 16th edition board supplementary bonding in place all tests comply to those laid out in Regs 2008 as amended, would be to risk asses the usage of the installation for example if its a rented property then the addition of RCD protection would be appropriate especially if its students that have been let loose from the family home , RCD's are not the be all and end all , that is why it is very important for the test reading to be with the readings laid out in BS7671 if an RCD fails the circuit needs to disconnect in the required time ,this is why i feel the item in the event of high Zs readings RCD protection is one of the remedial actions ,this should be removed , we should finding out why the reading are above the maximum permitted and rectify that problem for example a shower circuit 32 amp mcb r1r2 reading 0.86 Zs 1.39 , cable run approx 10 meters , stick an RCD on it it will be fine , no there is obviously an problem , its this sort of thing im on about

 

[Adam W]

only if the circuit cables on the non-RCD side don't comply with 522.6.101 in other ways. then it's a code C3.

The sockets would need to be rcd protected anyway unless for a specific item of equipment - you're more likely to get a shock from handheld equipment plugged into a socket than from the socket itself.