I have an earth grounding pin outside my house and an earth wire running from it to my distribution board, however the wire is not connected to the earth rail (ground rail?) In the DB.

(The house is already earthed but a new earth pin was installed as part of a recent upgrade but never connected up for some reason)

I'd like to connect it. I'm thinking I can simply connect the earth wire to the existing earth rail and be done with it.

Does that sound ok?, or does there need to be a circuit breaker between the earth wire and the earth rail in the DB?

This is in New Zealand, btw.


  • What country are you in? – DoxyLover Dec 30 '15 at 2:02

basically the earth path provides a low resitance path for safety and if supplier has supplied an earth already in the incoming supply should be sufficient . RCD protection monitors live /neutral and will trip when unbalanced ..connecting an earth spike to earth terminal if instalation already earthed makeslittle to no difference as it is the loop resistance path that is imporatant and a local electricain should be able to carry out a loop impedence (z) test to confirm path is fine.


the wire should be directly connected. NEC 250.64

  • 1
    The OP's wording makes me wonder what country he's in. The NEC may not apply. – DoxyLover Dec 30 '15 at 2:02
  • Country: New Zealand. The house is old (prob 100 years). DB was upgrade from fuses to circuit breakers previously. All wires have been recently replaced. Electrician said there is an existing earth wrapped around some pipe going into the ground, but I can't see any "earth leakage circuit breaker". I guess existing earth must be wired straight into the earth rail. This country doesn't have a record for strict building standards (until recently...) So - I guess if you can wire the earth-pin wire straight into the earth rail, that means you don't need an earth circuit breaker? – codemonkey Dec 30 '15 at 3:12
  • @codemonkey -- modern differential breakers (ELCBs/RCDs/GFCIs) do not need an earth connection to function -- instead of measuring current on the bonding return, they measure the difference between hot and neutral. – ThreePhaseEel Dec 30 '15 at 3:33

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