David West
5 to 10 ohms is not a very accurate reading for a Ze test. Depending on what earthing arrangement you have, if it is TNCS then a maximum Ze should be 0.35 ohms, TNS is 0.8 ohms or TT systems where you have an earth rod in the ground with earth wire attached will be up to 200 ohms. So if your system is TNS or TNCS 5 - 10 ohms is very high irrespective of whether it is RCD protected or not. I would get a professional electrician to check it out properly with a view to contacting your supplier to make sure you have the correct earthing arrangement.
