Should the humble domestic MET (Main Earth Terminal) be retired

Should the humble domestic MET (Main Earth Terminal) be retired and be replaced by Green coloured Henley style connector block?

Things to consider

More electronics in the dwelling naturally leaking mA to Earth in normal operation

Connector block is safer as has no exposed terminals thus introducing an IP rating

With more and more PEN faults occuring on the network.  A domestic install could have the Earth/Earth Bond become a live conductor under fault conditions.  Under certain PEN fault conditions the MET could be at 230v nominal.  This also opens up the debate of

if a 16mm CSA Earth cable is wise if the tails are 25mm CSA.  (again 16mm CSA under PEN fault conditions)

As always please be polite and respectful in this purely academic debate.


Come on everybody lets help inspire the future.

  • There is very little point in insulating the earth marshalling blocks from a shock point of view

    The only situation where I can think it might possibly be helpful, is where it's located (or accessible from) outside the equipotential zone - so say the outdoor meter cabinet with a missing door. Although fixing the cabinet door might be a better solution.

       - Andy.

  • Quite so, but they do seem to be a thing of the past and I doubt that they would be used in any installation bigger than a domestic scale.