Consumer unit layout

[Belle427]

i have a split load cu installed with single rcd, at the moment the circuits are laid out as follows.
Rcd protected: 1x sockets, 1x induction hob, 1x oven, 1x boiler, 1x fridge freezer.
Not Rcd protected: 2 x lighting, 1 smoke alarm.

It is my thoughts to put the fridge freezer on the non rcd side as we had a nuisance trip whilst on holiday recently, and lost the entire contents.
Any tips on what you would do circuit wise?
It’s a typical new build with 1 ring main covering 3 floors, which is poor in my opinion but it’s got to stay that way sadly.

 

[sparkwright]

What you suggest with the freezer socket may be ok in principle, but could be a problem if the cable is buried in a wall at less than 50mm deep.

In my opinion, the best way is to fit an RCBO on the unprotected side of the cu to serve the freezer.

 

[Belle427]

It’s an added high level socket for the fridge freezer but yes there is roughly 300 mm of cable behind the dabbed plasterboard.

 

[AndyPRK]

When you say new build? how old?

Any pictures?

You could fit RCBO's to the light circuits

 

[securespark]

A new-build should not have a single RCD in the CU, to have that, it would need to be at least a decade old, installed under the 16th Ed. Regs.

 

[Belle427]

Sorry, yes it’s about 10 years old, not strictly a new build but your typical modern housing estate.

 

[flameport]

with 1 ring main covering 3 floors,

That is actually how rings were intended to be used - one for all of the socket outlets in the house.

we had a nuisance trip

If the RCD trips it is either due to a fault or poor design (such as too much equipment on a single RCD).
Given you were on holiday at the time a fault is more likely as little or nothing else would have been in use then.
Could even be the freezer itself.
Moving items to non-RCD circuits is not a solution.

It is my thoughts to put the fridge freezer on the non rcd side

If you must do that, you'll need to be quick - the nonsense about specific socket outlets being permitted with no RCD is removed from January 2019.
Cables in the walls already require RCDs, and from January all lighting circuits in dwellings will require RCDs as well.

Any tips on what you would do circuit wise?

Sling the RCD and existing MCBs away, replace with 7 RCBOs.
7 because the smoke alarms can go with one of the lighting circuits, so that in the event of power failure to that circuit, people will notice immediately.
If the smoke alarms are original to the property, they also need to be replaced, as they have a lifespan of 10 years.

 

[AndyPRK]

What’s changing in jan regarding light circuits?

 

[DetlefSchmitz]

I don't think it's light circuits. I think it's the no special exceptions to the 'RCD required for sockets' rule.

 

[JohnW2]

What’s changing in jan regarding light circuits?

Indeed. Unless I missed it, there's no requirement for lighting circuits, per se, to be RCD-protected in 18th. As has been said, the main change is removal of the 'loophole' regarding 'dedicated sockets'.

Of course, if one really wanted to, I presume that one could hard wire a freezer (or whatever) into an FCU, and hence avoid the requirement for RCD protection (unless, of course. there was 'new' buried cable requiring RCD protection, anyway).

Kind Regards, John
Edit: Whoops - I hadn't noticed Detlef's post - but I suppose it does no harm for two people to say essentially the same thing!

 

[Belle427]

That is actually how rings were intended to be used - one for all of the socket outlets in the house.


If the RCD trips it is either due to a fault or poor design (such as too much equipment on a single RCD).
Given you were on holiday at the time a fault is more likely as little or nothing else would have been in use then.
Could even be the freezer itself.
Moving items to non-RCD circuits is not a solution.


If you must do that, you'll need to be quick - the nonsense about specific socket outlets being permitted with no RCD is removed from January 2019.
Cables in the walls already require RCDs, and from January all lighting circuits in dwellings will require RCDs as well.


Sling the RCD and existing MCBs away, replace with 7 RCBOs.
7 because the smoke alarms can go with one of the lighting circuits, so that in the event of power failure to that circuit, people will notice immediately.
If the smoke alarms are original to the property, they also need to be replaced, as they have a lifespan of 10 years.

Good idea, any brands to avoid when choosing a new cu?

 

[flameport]

What’s changing in jan regarding light circuits?

All lighting circuits in domestic premises require 30mA RCD protection.

Unless I missed it,

 

[AndyPRK]

give us a picture of your old one.

Maybe able to get RCBO's to fit that. Much easier

 

[Belle427]

 

[flameport]

While RCBOs for that are theoretically available, installing them in there will be a nightmare.
Replace the entire thing - most of the cost is the RCBOs, the box they fit into is a tiny fraction of the total.