My own rewire cu advice

[peterb2428]

Hi,

New property time for new consumer see attached pics as need some advice. This might be a bit long winded but here goes. three cu's first one contains main switch and the following 30+30+5+15+15amps connected to standard black meter as seen in pic at top, then from the supply another off peak meter is fed and also a radio switch for the off peak - this feeds another 2 cu's via henley blocks containing a 4 unit 15+15+15+15amps and a 2 unit 15+15amps,

All are metal clad and the main unit has a seperate RCD switch after the meter,

Advice i need is as the meter goes to the rcd and the tails are short i was looking at putting in a 100A DP Supply Isolato rthen connecting to cu but i am unsure whether to put two boards back one for house one for all the 6 radials or whether to try and incorporate all into 1?

Advice please guys.

 

[super_stuey]

Is there storage heaters in the house? Id bet my life on the board with the 15amp radials was/is for them so that mite influence your descision.

 

[peterb2428]

Is there storage heaters in the house? Id bet my life on the board with the 15amp radials was/is for them so that mite influence your descision.

Yes mate the two other cu's are for them 6 outlets in total.

 

[SirKit Breaker]

Hi mate,

Without seeing the job in hand. I would look to put the heaters into one CU, using 16a MCb's, one for each heater, and fit a RCD main switch in the CU, its not the end of the world if the heater CU RCD trips, and its cheaper than using RCBO's but then the cost options are one for your customer to consider.

All the rest i would again shove into one CU, dual or triple split load depending on how many circuits etc, again RCBO's would be better but there is a cost involved. This way you end up with 2 CU's instead of a few which looks messy.

Does the install require a RCD on the incomming supply?, i have come across plenty fitted like yours on mainly council or ex council owned properties and found the Ze to be well in spec, if the Ze is in spec for the supply then bin this RCD and use the ones in the new CU,s for protection. I would also go with plastic CU,s not metal.

Cheers........Howard

PS dont forget bonding upgrade if applicable.

 

[peterb2428]

Hi mate,

Without seeing the job in hand. I would look to put the heaters into one CU, using 16a MCb's, one for each heater, and fit a RCD main switch in the CU, its not the end of the world if the heater CU RCD trips, and its cheaper than using RCBO's but then the cost options are one for your customer to consider.

All the rest i would again shove into one CU, dual or triple split load depending on how many circuits etc, again RCBO's would be better but there is a cost involved. This way you end up with 2 CU's instead of a few which looks messy.

Does the install require a RCD on the incomming supply?, i have come across plenty fitted like yours on mainly council or ex council owned properties and found the Ze to be well in spec, if the Ze is in spec for the supply then bin this RCD and use the ones in the new CU,s for protection. I would also go with plastic CU,s not metal.

Cheers........Howard

PS dont forget bonding upgrade if applicable.

Thanks Howard,

Why RCD the heater radials? and why dual or triple? as there is only 6 other circuits . and yes i will use the rcd in the new cu for the main curcuit but the problem is that the tails out of the standard meter are not long enough to reach new cu so was thinking of installing a 100amp double pole isolater before cu.

Also will go plastic but currently got swa wired into metal clad cu and not sure how i want to connect this to new board.

 

[flukey]

Thanks Howard,

Why RCD the heater radials? and why dual or triple? as there is only 6 other circuits . and yes i will use the rcd in the new cu for the main curcuit but the problem is that the tails out of the standard meter are not long enough to reach new cu so was thinking of installing a 100amp double pole isolater before cu.

Also will go plastic but currently got swa wired into metal clad cu and not sure how i want to connect this to new board.

imo i would employ the services of a registered electrician

 

[peterb2428]

imo i would employ the services of a registered electrician

Thanks Flukey most helpful only asking and yes i am qualified perhaps you could answer instead of being predictable and maybe point out why you feel flippant?

 

[SirKit Breaker]

Thanks Howard,

Why RCD the heater radials? and why dual or triple? as there is only 6 other circuits . and yes i will use the rcd in the new cu for the main curcuit but the problem is that the tails out of the standard meter are not long enough to reach new cu so was thinking of installing a 100amp double pole isolater before cu.

Also will go plastic but currently got swa wired into metal clad cu and not sure how i want to connect this to new board.

RCD the radials because the cables require RCD protection if they dont meet the exlusions in the regs.
Dual RCD board to minimise inconvenience in the event of an RCD trip, again as per the regs.
I only stated dual or triple because the more RCD's you have the less inconvenience occurs, in your case a dual will do. I would fit longer tails, if you wish to keep the RCD then make sure it is rated higher than the ones protecting the circuits or you are in for a right laugh. If you wish to fit an isolator then ring the supplier and get them to do it for you, this will save you messing about with their dangerous bits and breaking any laws applicable. Join your SWA to suitable sized T&E in a suitable joint box, then connect T&E into CU using an additional CPC of the correct CSA if required to bond the armour.
Oh and dont forget to inform LABC if you are not Part P self cert.

Happy to help.


Cheers...........Howard

 

[flukey]

wasnt being flippant, you said you dont know how to connect swa to an insulated cu. if you dont like the answers dont ask the questions. good luck with the job, think you may need it

qualified doesnt equal experienced

 

[peterb2428]

wasnt being flippant, you said you dont know how to connect swa to an insulated cu. if you dont like the answers dont ask the questions. good luck with the job, think you may need it

qualified doesnt equal experienced

lol-didn't mention "dont know how to connect swa" read again.

 

[flukey]

Also will go plastic but currently got swa wired into metal clad cu and not sure how i want to connect this to new board.

for someone of your obvious experience, judging by your previous comments you are asking some very very basic questions so stop being flippant and sarcastic when you get a legitimate answer.

read your original post and tell me how qualified you sound

 

[peterb2428]

for someone of your obvious experience, judging by your previous comments you are asking some very very basic questions so stop being flippant and sarcastic when you get a legitimate answer.

read your original post and tell me how qualified you sound

Flukey no disrespect but if all you have to pick on is how i am gonna connect my swa then fine but if you have anything constructive to say -PLEASE TRY as for previous post from Howard.

Howard -thanks

I's a bungalow so only 6 cuircuits on main board and are you saying you can't fit an isolator without notifying DNO??

And yes discrimination is always wise.

 

[flukey]

youve had all the help youll get from me with your attitude.

if you want me to fit your isolator for you let me know as even though i am obviously not fully qualified in your eyes i know the answers to your questions and can do the work

good luck

 

[peterb2428]

youve had all the help youll get from me with your attitude.

if you want me to fit your isolator for you let me know as even though i am obviously not fully qualified in your eyes i know the answers to your questions and can do the work

good luck

Have a nice evening

Howard/Flukey - why again would the radial curcuits for the storage heaters need RCD?? surely there not general use sockets in fact they would be 20amp dp switched sockets labelled Storage heater?

Going for a beer now but looking forward to more advice - but please not you Flukey

 

[flukey]

take gn3 or osg with you and read up on the questions you are asking, first year stuff

 

[peterb2428]

take gn3 or osg with you and read up on the questions you are asking, first year stuff

Hi,

Think i need to as i am still not sure any advice was helpful? Although to be fair Flukey you never really offered any!
Regarding the isolator does anyone know price/time as would like to get the tails changed (modern colours and all that) but obviously these come from sealed meter.

Maybe i should have asked for advice from the screwfix forum

Thanks for any help

 

[peterb2428]

take gn3 or osg with you and read up on the questions you are asking, first year stuff

You could always enlighten me with your superior knowledge

 

[flukey]

i would but im not fully qualified am i

as per my first post you need to enlist the help of a registered electrician as this work is notifiable

be my guest and try the screwfix forum if you think me unhelpful

 

[Spudnik]

I cant believe i am reading this, especially after recent threads.

IF anyone wishes to help the OP then please do, otherwise move on

 

[ezzzekiel]

why again would the radial curcuits for the storage heaters need RCD?? surely there not general use sockets in fact they would be 20amp dp switched sockets labelled Storage heater?

providing you surface mount the cables or run in steel conduit, swa then no you wont need a rcd.
any CABLES buried less than 50mm will require rcd protection. 522.6.7

isolator will cost upto £60 and can take anywhere from 2-6 weeks to be installed by dno

fit two c/u one for property other for storage heaters, storage heaters fed from 5th terminal from meter and common neutral, may find water heating ran from storage c/u too and heated at cheap rates with a timer from main c/u to heat during day.