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.

Parents
  • I would ask, which is the MET?

    House supply has a traditional MET with some very weedy looking copper from the PILC, but it is 4 x 4 mm². I don't quite see how it could be avoided. A length of 16 mm² cable takes it to a switch-fuse in an adjacent cabinet. More importantly, loads of bonding comes together in another terminal in the house. I think of it as a "building earth terminal", but there seem to be other names too.

    My garage supply has no bonding so the earthing conductor goes from the (PME) intake to the main board. I suggest that there is no MET.

  • Hi Chris

    In my eyes I would say a MET block is one of these.

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