Blair wrote:
I am adding two extra double sockets to my kitchen ring main and I was
proposing to fit two 20 amp junction boxes to enable me to add the extra
sockets.
A friend said I should fit 30 amp junction boxes instead of 20 amp
Is this essential?
So far I have not seen any 30amp boxes in B&Q or Wickes

I'm surprised - they're readily available: eg

http://www.screwfix.com/app/sfd/cat/...13013&ts=23717

These have three terminals; the 20A ones you've seen typically have
four, right? (for use with lighting circuits)

David