Adding a second consumer unit off the main switch

[DomB]

Hi all,

I need to add a second, 4 way, consumer unit at a customer's house. I have bought the unit and some 16mm tails. Would I be able to add those 16mm tails into the main switch of the primary CU or would I need to put a Henley block in the orginal tails?

Thanks very much

 

[Sparky Ninja]

would need to be connected into the supply side, and would depend on ratings, space etc according to the main switch you have.

Using henley blocks would be a much better practice IMO

 

[DomB]

Thanks Widdler.

I figured just connecting the tails into the primary CU's main switch would mean I wouldn't have to pull the supply fuse or cut the main tails.

When you say it would depend on the ratings - I guess that would be of the primary's main switch there?

 

[Knobhead]

It’s a case of the capacity of the terminals than the rating of the switch. If you can get two sets of tails in the terminal then loop off the primary board.
To be honest I’d go for the Henley blocks, it’s then obvious to anyone following you to see what’s going on.
But then I’m not paying for it.

 

[SimpleSimon]

I'd be very impressed if you could get two sets of tails in a main switch!

 

[telectrix]

mee too. henleys every time.

 

[DomB]

Thanks chaps. Henley block it is.

 

[white armour]

Hi DomB, if the service fuse is rated at 100Amp would use 25mm tails, would also use 16mm main earth and upgrade bonding to 10mm.

Regards wa

 

[Sparky Ninja]

It’s a case of the capacity of the terminals than the rating of the switch. If you can get two sets of tails in the terminal then loop off the primary board.
To be honest I’d go for the Henley blocks, it’s then obvious to anyone following you to see what’s going on.
But then I’m not paying for it.

It's the rating that dictates the capacity.