TN-S?

[Aragorn84]

But isnt the point that you then pay a higher standing charge or a higher daytime rate as a result?

You dont get something for nothing, and certainly not from an energy supplier.

If what you say made any sense, then the entire country would be on E7, just to ensure that any power consumed after midnight and before 7am was cheap.

 

[333rocky333]

So what is the problem with metal clad box

Sorry, not good at explaining it.

With TT and a earth rod ( which dont affect you) basically the rcd needs to protect the meter tails if they enter a metal cu, so the rcd has to be external to the cu.,
If plastic cu used in TT, then the meter tails are ok non rcd protected and the rcds can go in the cu.

All to do with the high earth resistance of TT systems,
and the possibility of the metal cu casing becoming live for some reason or other.

 

[flameport]

For most of the E7 tarrifs, you need to use around 25% of your electricity at night before any savings are made, and realistically at least 50% at night before the savings are actually worthwhile.

This means that unless you have electric heating which charges at night, the E7 tarrif will actually cost more than a single rate.