Minimum cable size in a henley block?

[noidea]

Evening all

I was wondering if there was a minimum size of cable that can be put into a Henley block. The reason I ask is I have just installed some new electrics out to my garage. I had a couple of spare ways in my house CSU (which has a 30ma RCD) and I have run a 6mm twin & earth out to the garage from a 30amp MCB. The new CSU in the garage which has a ring and lighting circuit on it also has a 30ma RCD. I have since found that this is causing me problems when trying to test the RCD because the house RCD is more sesitive and trips 1st.
I have since read on here and other places that having 2 30ma RCDs on the same circuit is not necassary. (obvious when you think about it I suppose)
So I was wondering if I could put the 6mm straight into a henley block and run that to the garage and bypass the main CSU.
But now I think about it, wouldn't the 6mm twin & earth need to be RCD protected??
Man this electrics is realy hard to get your head round. Just when I think I am getting somewhere I realise there is so much more.
So can I put the twin and earth in the block or do I need to lose the garage RCD?
Or shall I just shut up and go away??

 

[Guest123]

No, you couldn't put 6mm straight into the henley as there would be no overcurrent protection to the cable other than the suppliers main fuse which could be as much as 100A!

 

[Sintra]

Probably easiest to keep the set up as in the house and put a main switch into the garage cu in replace of the main 30mA RCD.

 

[Guest123]

Probably easiest to keep the set up as in the house and put a main switch into the garage cu in replace of the main 30mA RCD.

Agreed.

 

[High Tower]

Probably easiest to keep the set up as in the house and put a main switch into the garage cu in replace of the main 30mA RCD.

Agree here too