PE and water pipes (yet another earthing thread)

[Johno1066]

Lost cause if you are in the UK you will have an earthing system cotrolled by the British standard regulations for the wiring of premises. Therefore neutral grounded or Earthed in another language at the transformer secondary only, so there can always be a small difference between neutral and ground earth as earth is not a current carrying conductor but the neatral is so depending on the load on the neutral conductor there will be a certain volt drop at a distance which will create a small potential difference between the two. There also should be an earth terminal in your distribution board which could be connected to the ground terminal of your inverter. Problem arises if you have an earth leakage circuit breaker between the inverter and your panel to feed whatever circuits you need to you will always trip that breaker because the inverter will internally connect its neutral to ground and that will cause some current to flow through the ground conductor thereby imbalancing the current through the earth leakage breaker.

 

[Johno1066]

Lost Cause sorry I will take back what I said about the earth leakage breaker tripping as it will if the neutral and ground are bonded in the panel like in the USA. I would just ground your inverter to your main Ground Earth bar and your neutral will only bond to ground once you are getting power from your inverter and I take it you would be disconnected from your grid at that time.