Advice on replacement consumer unit please?

[smeegazzle]

Hello,
I need to arrange for a new consumer unit to be installed in a rented house. this will be installed by an electrician but my question is does it need to be a normal split unit with a single RCD or a full 17th edition box?

As the unit is to be fitted to comply with a council instruction and all that they have asked for is a box with RCD and MCB's I am hoping to use a Wylex split box that I already have....

The question really boils down to is 17th edition applicable to replacement consumer units as well as new installations?

Thanks for any advice - Gary

 

[ColJack]

there's no such thing as a "17th edition box".. though many dual RCD boards claim to be..
single or non-RCD units are also compatible with the use of RCBO's on the circuits that need them.. but RCBO's are more expensive so the cheaper option is often a dual RCD board....

it all depeds on your installation..

if it happens to be wired in MICC or the newer ali-tube cable or of wooden studwork construction then you don't need RCD's on some of the cables.

if you can get RCBO's for the wylex you already have then that's an option for the circuits that need protection..

 

[Chri5]

A CU chassis is not expensive, it's what it contains !

Your existing CU can have the RCD removed and all circuits changed to RCBO's, which at £30 each (trade cost) x circuit volume could be expensive.

Split boards have 2 x RCD's to avoid danger issues with single point of failure. As in the RCD pops no circuits work, light off, old lady falls down stairs.

A split board designed correct would loose only half the circuit when a RCD trips, and by simple design 1st floor and Grd floor lights would be on different RCD's- so one set of light circuits would remain working.

As a landlord you are responsible for safety in your building. It can be claimed back off the tax bill- so do it right and then your have a hassle free electrical system for years (and the yearly safety cert will make sure).

You don't mention if the house is rented as one unit or as a multiple occupancy unit- electrically there's a big difference.

On the assumption that it's a whole unit rental I'd suggest.

Split board plus direct way.

Smoke detectors on RCBO direct then fanning the rest of the circuits between the 2 x RCD rails.

But if you want the best design and the clearest way of future proofing the job, make every circuit an RCBO.

The advantage is simple. An RCBO will only trip it's own circuit.

 

[Click-Sure]

I only do RCBO installs now. I have done a few dual-split load installs before, but I've gone off them bigtime, just really dont feel it fully complies.

 

[SparkyNinja]

I only do RCBO installs now. I have done a few dual-split load installs before, but I've gone off them bigtime, just really dont feel it fully complies.

Is there a specific reg that makes you feel this way or is it preference?

 

[ml3872]

what are the steps to 'replace a consumer unit'? take note, the 100ma fuse at the intake position is only subject for the distributor to disengage. question is; how would the electrician start replacing the consumer unit if this is the condition?

 

[ricicle]

take note, the 100ma fuse at the intake position is only subject for the distributor to disengage

I think that fuse will be disengaged a long time before the distributor gets to it !

 

[Chri5]

what are the steps to 'replace a consumer unit'? take note, the 100ma fuse at the intake position is only subject for the distributor to disengage. question is; how would the electrician start replacing the consumer unit if this is the condition?

Do you mean a tt system with 100 ma rcd and earth rod?

The cu sits downstream and provides discrimination via 30 ma rcds or rcbos.

 

[plugwash]

I only do RCBO installs now. I have done a few dual-split load installs before, but I've gone off them bigtime, just really dont feel it fully complies.

Is there a specific reg that makes you feel this way or is it preference?

As I understand it there is a reg that states you should minimise inconviniance in the event of a fault but it is never explicitly state how far you should go in your attempts to minimise inconviniance.

The powers that be seem to have developed the opinion that a single RCD board is not compliant with this but a dual RCD board with the circuits somewhat arbiterally split between the RCDs somehow is. I find this a dubious position to take.

 

[ban-all-sheds]

Hello,
I need to arrange for a new consumer unit to be installed in a rented house. this will be installed by an electrician but my question is does it need to be a normal split unit with a single RCD or a full 17th edition box?

It needs to be whatever the person you choose to do the work says it needs to be.

End of.

 

[Electrifying]

Hello,
I need to arrange for a new consumer unit to be installed in a rented house. this will be installed by an electrician but my question is does it need to be a normal split unit with a single RCD or a full 17th edition box?

It needs to be whatever the person you choose to do the work says it needs to be.

End of.

Not like you, BAS - I think you'll find that 2 1/2 years on he's had it replaced by now

 

[ban-all-sheds]

I blame ml3872, ricicle, Chri5 & plugwash..