Consumer unit fuseway / ring-main

[blacksheep]

Hi all,

Ok regulation wise, and theoretical wise (which seems ok IMO):

Is it ok to 'double up' one of the fuseways so that you end up with 4 L inserted into it. Its still protected by a 32A mcb but two rings will then be on 1 fuseway.

I could of broke into the existing ring and extend it but this is very awkward considering all the leads leave the CU and go straight into ceiling (half inch away)

Did intend to originally use the previous 30A cooker fuseway, which was a cooker but is a 1 socket radial in kitchen now but the cable in that fuseway is too heavy to add any more cable.

Thanks for advice!

 

[comms]

Why not remove one of the old ringmain legs from mcb & join to one of new ringmain legs.
Then put the remaining new ringmain leg into mcb along with other old ring leg.

Hey presto you have extended the ringmain.

 

[Adam_151]

Why not remove one of the old ringmain legs from mcb & join to one of new ringmain legs.
Then put the remaining new ringmain leg into mcb along with other old ring leg.

Hey presto you have extended the ringmain.

Other than it being a bit more conventional and easier to work out whats going on, thats an inferior way of going about things in terms of VD, EFLI, etc.

Not sure I like the idea of a 'double rfc' though, while I can't see a technical problem with it as long as the expected load doesn't exceed 32A, and you can terminate the conductors alright, it is very irregular!

Certainly cause one of those 'whats going on here then?' moments when PIRing

I'd have a look at what you can do with the lighting circuits, is the load light enough that they can become one? or can they be fed from a pair of FCUs on a 15A radial?

 

[blacksheep]

Its a 6way CU and has light,lights,shower,bell,cooker and socket ring-main

I didnt want to join up to the old ring as id have to add a single connector block within the CU which is already small and cramped. Although I could do this is there any serious advantage to what I have already done?? Surely the way I have done it would give a better connection to the new ring (although both work)??

If required, I guess I could combine the lights circuits, or use the bell. I guess the bell is most logical to use as it already has its own fused outlet nearby so upping its mcb wouldnt stop protection. Id assume the best way to do this would be to just use the bell fuseway and just leave the bell in there (and obviously up the mcb)?

However apart from the reduced load capacity of having two rings on one mcb are there any problems with my original setup? All the heavy current stuff (washing machine, tumble,dishwasher and iron) are going to the new ring anyway. Although what I have done works, I would like you experience guys opinion on it!

Thanks

 

[bernardgreen]

Move the bell transformer onto one of the lighting circuits and change the now redundant MCB for 32 amp and put the new ring into that.

 

[blacksheep]

Funny as I have listed the existing Fuseways today I have noticed the Bell, probably rushing to get the room done and power back on yesterday!

But although I think Bernards way is correct id appreciate if we discussed it a bit (youll tell me to get a book! haha):

1) My method I have done. The downside is reduced capacity and just not very neat nor easy to understand for a leccy who opens the box next..

2) My other idea with the bell on the ring is not good because, although only a foot away the wire connecting the fused connection box is only done with lighting wire. So not protected!

So considering the situation bernards solution is better because all fuses are correct size for capable?

thanks.

 

[JohnD]

you could put the bell transformer on the ring using an FCU at 3A.

 

[plugwash]

Hey presto you have extended the ringmain.

NO, you are liable to create a very unbalanced and long ring, this is not a good thing.

As for doubling up rings it is unclear whether it complies with the regs (basically it comes down to whether you consider it two circuits or one unconventional circuit) but it is perfectly safe and most installations that require such measures are probablly noncompliant in other ways anyway.

 

[reggie perrin]

Why not remove one of the old ringmain legs from mcb & join to one of new ringmain legs.
Then put the remaining new ringmain leg into mcb along with other old ring leg.

Hey presto you have extended the ringmain.

Did a PIR recently where this had been done inadvertently and there were some really queer results being thrown up.

 

[blacksheep]

The ring is long enough as it is, there is only one for the whole house. Thats why I thought the way I done it would be a better connection just didnt know if that brought up any other issues!

To be honest the whole ring idea stresses me out, one bad connection on a socket and the capacity is halved and the mcb/fuse is higher! Saying that though im a bit paranoid! When I did the room I did a conntinuiity check with a multimeter and I think I was picking up about half an ohm on the earth side and less on the L and N. I was still thinking to myself this is hardly a proper load test!
Mind 23A being drawn with 2.5mm is still quite a lot, im sure you guys have seen this a few times? (dodgy rings)

Think ill leave it as I have done it then, although bernards plan would give me an mcb to switch the room off, which is nice.

 

[blacksheep]

Also another query:
What protects the CU? Is it the Electric companys main fuse outside (mine says 60/80A). Does this imply my CU is ok up to 60/80A ?

Just I was slightly concerned at using a spare fuseway (with the bell swapover idea) because then id have two socket runs (as well as the existing loads) creating a potential of another 30A on the board.

 

[JohnD]

Does this imply my CU is ok up to 60/80A ?

show us a pic of the CU and the cables around it and the meter and we might have an idea
//www.diynot.com/forums/viewtopic.php?t=99672

id have two socket runs (as well as the existing loads) creating a potential of another 30A on the board.

the number of sockets you have, or the number of circuits, does not have much effect on the loading. You probably still have the same number of washing machines, fan heaters and ketles, whichever way they are distributed among your circuits.

 

[Space cat]

Have you checked the floor area that will be covered by your new, bigger ring?

Even if it's under the 100 sq m limit, I would still move the bell transformer onto a lighting circuit (or an FCU) then put the new ring on its own breaker. Do you ever go out and leave a washing machine to finish its cycle? Wouldn't it be nice to know that if it spits its dummy out and trips the breaker your other sockets will still be on. Or would you rather come home and find that your freezer is defrosting itself, the chicken in the electric oven is only half cooked and, as if that wasn't bad enough, your VCR didn't record the film you've been wanting to see for ages!

 

[blacksheep]

Its only a small room about 2.5 by 2m with 7 sockets total but I still agree with you its a better solution on seperate breaker.

Ok heres is some pics, although not topic related I have also included some others of broken bonding I have found and the crap shower install (well look wise anyway). I have dissed the shower when I moved in as it just buzzed and done nothing. Looking at the bonding though im glad I did as that needs sorting first before shower.

Hope you got a decent connection these pics are over 2meg each (havent downscaled them at all)

Consumer unit pics (with mcb left in fuses are too big to get cover off!) :
http://www.zen44027.zen.co.uk/DSCN0655.JPG
http://www.zen44027.zen.co.uk/DSCN0656.JPG
http://www.zen44027.zen.co.uk/DSCN0658.JPG
http://www.zen44027.zen.co.uk/DSCN0657.JPG (Notice my doubling up)

Shower
http://www.zen44027.zen.co.uk/DSCN0654.JPG

Underbath earth bonding
http://www.zen44027.zen.co.uk/DSCN0650.JPG
http://www.zen44027.zen.co.uk/DSCN0653.JPG

 

[JohnD]

that CU is max load 60A, max load on any circuit 32A

I'm pleased to see you have the push-on plastic covers over incoming terminals, but the copper you can see above the main switch is permanently live, so be careful not to touch it!