Distribution Board (Help)

[Durkee Atwood]

The present electrics in my house all be it safe is a bit of a mess. There have been a number of additions and the distribution board is comprised of several fuse boxes. I hate it with a passion as there are cables everywhere and I can never remember what does what because the fuse labels have been written over by previous house owners/contractors.

I want to replace the fuse boxes with one split-load distribution box with tidy wiring. I have such a box and I intend to arrange things as follows:

Main Switch 100A} [40A MCB (Cooker)] [32A RCBO (Shower)] [20A MCB (Fridge)] [6A MCB (Lights UP] [6A MCB Lights DOWN] [spare] [spare]

RCD 80A} [32A MCB (Ring Main UP)] [32A MCB Ring Main DOWN)] [16A MCB (Garage)] [16A MCB (Towel Rail)] [6A MCB (Garage Lights)] [spare] [spare]

Can anyone see anything wrong with this configuration?

Thanks for looking.

 

[batty]

Is this a high intrgrity c/unit and if so why is cooker not RCD protected and also other circuits?

 

[NozSpark]

YES...

It looks like you are wanting to use a split load consumer unit.. the way you show it you will have several circuits without RCD protection.. bear in mind that all socket outlets <32A require RCD protection and all burried cables <50mm require RCD protection (unless they have earthed mechanical protection)

This is a major job that you would be undertaking, and you need to fully understand the regs that apply.. more reading required..

 

[a1spark]

Durkee . you say the Electrics although in a bit of a mess are Safe ? have you inspected &Tested them to confirm this.

Also it looks like you are still designing and installing to 16th edition standard .

 

[M107]

Couple of other things to consider

1. Main equipotential bonding, is it correctly sized or even in place.
   
2. Can you safely isolate the meter tails while doing the cu change.
   
3. What is the supply type & is Ze of a good ohmic value.
   
4. Are you aware you'll have to notify the proposed work with building control prior to starting the work.
   
5. Your proposed lay out of the cu will probably not comply (haven't seen the install) unless the first 5 circuits are put on rcbo's.
   
6. Are you able to test & certificate the completed work.
   

 

[Durkee Atwood]

All good points. Getting some professional help with this one and resigning myself to the position of apprentice/tea maker.

 

[SPECIAL LOCATION]

All good points. Getting some professional help with this one and resigning myself to the position of apprentice/tea maker.

What make of CU (fuse board) is it....

have you considered finding the price of some RCBO's in place of the MCB's on the non-RCD protected side....

You would also need to separate the socket circuits onto different RCD / RCBO's

 

[AAAMUSEMENTS]

More usual to have the shower on a 40amp and cooker on a 32... have you checked what size cables are currently supplying these appliances?

 

[fivewood]

Should really split the lighting circuits across the RCDs for safety.

ie Upstairs lighting on one, downstairs lighting on the other

That way of one goes, there will still be light somewhere in the house

 

[fivewood]

OK Ive just read that again

Ignore me - its early!

Thought it said you had both lighting circuits on a RCD :innocent

 

[paul b b]

durkee, sounds like you are getting split and dual mixed up, its the latter board you want, dual meaning dual rcd, thus, you will have all circuits protected by an rcd.

also as othere have said, make sure bondings are in place and upgrad tails if nessasery.

you may have a problem with your lights and may endup having both circuits on a 10A if you have a borrowed netrul, unless you run a new netral in.

 

[Durkee Atwood]

What make of CU (fuse board) is it....have you considered finding the price of some RCBO's in place of the MCB's on the non-RCD protected side....

You would also need to separate the socket circuits onto different RCD / RCBO's

Hi,

Type: Clipsal CU it has a plastic rail but the MCB's clip into it well and don't just rely on being screwed to the copper live terminal bar. It's not a top of the range unit but better than some.

Yes, I could fit RCBO's to the non-RCD protected side to be fully compliant and I am looking at using these (pricey) units.

I take your point about the socket circuits.

 

[Durkee Atwood]

More usual to have the shower on a 40amp and cooker on a 32... have you checked what size cables are currently supplying these appliances?

Hi,

Yes, on checking 17th edition compliance I might go for RCBO 40A for both the cooker and the shower. I am using 10mm cable and the run is under 10M for both. In fact it is more likely that I will fit RCBO to the complete non-RCD protected side.

There seems to be two schools of thought about what is and what isn't 17th compliant. One guide shows that two RCD protected loads are fully compliant and another states that it is only partly compliant. Again with the above configuration a guide shows this to be fully compliant. However, another guide states that only CU's with all RCBO's is fully compliant.

I have a member of this site coming to see me on Tuesday to look at what I have got and make sure that I am on the right lines.

Cheers

Jan

 

[Durkee Atwood]

Durkee . you say the Electrics although in a bit of a mess are Safe ? have you inspected &Tested them to confirm this.Also it looks like you are still designing and installing to 16th edition standard .

Hi,

I have had it tested by professsional electrician so that I didn't miss a trick.

Well, I suppose being partly compliant with 17th edition is strictly 16th edition but on reading the regs I am looking at RCBO's on the non-RCD protected side to bring it into the right area (see images).

 

[AAAMUSEMENTS]

Hi,I have had it tested by professsional electrician so that I didn't miss a trick.

Well, I suppose being partly compliant with 17th edition is strictly 16th edition but on reading the regs I am looking at RCBO's on the non-RCD protected side to bring it into the right area (see images).

If you can find two spare ways, then it may be cheaper to put in a second RCD.

If you don't have the space then RCBOs are indeed the only (expensive) solution.

 

[a1spark]

All good points. Getting some professional help with this one and resigning myself to the position of apprentice/tea maker.

And one of the most important jobs that one is,..,to be sure !! Durkee..

 

[paul b b]

if cost is an issue, screwfix have a 17th board for 80 qiud fully loaded

 

[AAAMUSEMENTS]

if cost is an issue, screwfix have a 17th board for 80 qiud fully loaded

Is that the Wylex one? If so I bought one and the quality looks about comparable to the B&Q

 

[paul b b]

i have fitted one and thought it was ok, intrested to see what others think though

 

[AAAMUSEMENTS]

i have fitted one and thought it was ok, intrested to see what others think though

Indeed, I will reserve judgement until I fit it.

Just made me wonder why I spent the extra on the Wylex, for the same basic quality (and probably identical MCBs) the Volex would have been sufficient?