Have been working on 2 flats in sunny Salcombe which is doing my head in. When I test for Zs using my Megger 1502, I keep getting a reading of 1700 ohms in both flats. Now Ze is coming in at 0.95 ohms ( I also tried this for N/L and got 0.1 Ohm), PFC is at @0.45 KA PSCC is @ 0.96KA. The supply is TN-s split from a cast iron box into upstairs and downstairs flats (though western power have now changed this due large hole in box - not had a chance to re-test since). One flat has new CU, the other a mini CU to supply single socket whilst building works carry on. Thinking that my test gear was knackered I have also had this re-calibrated and it was fine. Have also checked it against standard circuit in my own property - no problems. R1+R2 readings are fine on all circuits, tried replacing RCDs, and testing for continuity around CU and through RCDs - no problems. Also checked test leads and tried testing at back of sockets instead of using plug-in test lead - odd readings prevailed
So at the moment I'm at a complete loss as to how to explain the odd readings I'm getting when using the non-trip Zs function. It just doesn't add up, so if anyone can shed some light on this, it would be much appreciated.
So at the moment I'm at a complete loss as to how to explain the odd readings I'm getting when using the non-trip Zs function. It just doesn't add up, so if anyone can shed some light on this, it would be much appreciated.