Question on connecting up 2nd consumer unit

[sambuca2907]

Hi all - just wondering if I could get some advice.

I have installed 3 new circuits in an extension - a kitchen - lighting, ring main and cooker (gas so just 13A elec start). The existing board only contains MCB's, and my new circuits need to comply with 17th edition regs, so need RCD protection throughout.

The existing board is a nightmare... the electrics in the house I have come across are condemable so I have no wish what-so-ever to touch these! The guy who lives in the house "did a bit of electrics" years ago... so has done his own additions over the last 25 years...! I took the cover off a light fitting and found SIX lots of 1.5mm going into this... mangled together with choc-blocs and tape!! If I replace the existing board I just know I'm going to have earth leakage everywhere and never find the problems, so going towards putting in a new 17th edition board to cover the new circuits.

The question I'm asking is do you think it's better to do the following:

- Run 6mm from a 45A MCB in the existing board to the new board, and link back to the main earth terminal (Distribution circuit)

- Remove the tails from the existing board, add in Henley boxes and run a new set of tails to BOTH boards... abviously this option is going to cost more which I'm reluctant against as I've already priced for the job without this in mind!

Any help please?!

 

[marksparky]

if it were me id put in henley blocks much better job and then u also dont have anythin to do with existing board.

 

[sparks1234]

if it were me id put in henley blocks much better job and then u also dont have anythin to do with existing board.

Dont forget though if you do it this way to put in a new main switch before the henly blocks

 

[StagsHeadNo.4]

If you was to take a new cable from the excisting board I would suggest using 10mm, as more circuits (i.e elctric hob or out side power) may be added in the future. Also you would have to run an individual earth as it must be atleast half the size of your main tails coming from your sub-main. If you do come from the excisting board you would also have to issue a domestic Installation certificate for the old board ( That dosn't mean you have to test all the circuits just the one you've added. It just means more paper work).
You've also got to take into consideration the amount of room in the excisting board. It could be tight.

I would deffinatly just install a new henly block and put in your nice, fresh, easy to work with board. Hassel free. Good Luck.

 

[sambuca2907]

Couple of henley blocks and new tails! Thanks for the help!

 

[sparks1234]

Couple of henley blocks and new tails! Thanks for the help!

And main switch

 

[ajelec10]

Wylex do a great little unit designed to be a main switch connected via meter tails something like an RC32 i think??

 

[sparks1234]

Wylex do a great little unit designed to be a main switch connected via meter tails something like an RC32 i think??

Yep, bought one today

 

[Newpark7]

Is it called an RC32 only cant find one on google?

 

[sparks1234]

Might be and REC25, looking at their website

 

[Spudnik]

Dont forget though if you do it this way to put in a new main switch before the henly blocks

Can i ask why?

 

[Sintra]

An installation must be provided with a solitary main switch.

 

[m4tty]

An installation must be provided with a solitary main switch.

Solitary brother .........

 

[Spudnik]

An installation must be provided with a solitary main switch.

Is there a Reg number for that?

 

[Sintra]

Is there a Reg number for that?

537.1.4. A main linked switch or linked circuit breaker shall be provide as near as practicable to the origin of every installation as a means of switching the supply on load and as a means of isolation.

A main switch intended for operation by ordinary persons e.g. of a household or similar installation, shall interupt both live conductors of a single phase supply.