WebFeb 17, 2024 · Those Zs readings seem high for a domestic even with the Ze at 0.51. I agree - using my busted math I guesstimate ring length of over 110m for the 1.89-0.51=1.38 … WebOct 19, 2008 · I don't want to critise your electricians advice because I don't know all the info, but a slightly high Zs reading does not require a complete rewire - on the other hand you may have many other faults that he didn't tell you about/you didn't tell us about which has prompted that advice.
Determining Zs for a lighting circuit - Professional Electrician
WebAug 10, 2024 · I have calculated the max Zs values for these taking into account the tolerance permitted by Schneider and the C min value. I have used these as the Max Zs recorded on the test sheet. However when coding I have taken 80% of this value in lieu of the possible temperature rise under fault conditions. WebJun 9, 2024 · An d my instinct tells me that a measured Zs reading must be more accurate than a calculated one, since it will include all parallel paths under test. The contractor is happy to live test distribution circuits, so it seems they want to pick and choose. orangeisthenewlife
High Zs DIYnot Forums
WebJun 2, 2024 · However, the maximum Zs which would result in the required disconnection times by a 30mA RCD in response to a negligible-impedance L-E fault (which is analogous to the requirement with RM CB/fuse fault protection) would traditionally have been 7,667Ω (at 230V), presumably now 7,283Ω (with 'Cmin'). Kind Regards, John Edit: typo corrected WebAlthough for what is known as a TN earth system, the Ze reading is high, the difference between it and the Zs is 2.8 ohms. This is what is known as the R1+R2 value. A correctly … WebDec 9, 2010 · Check your Ze reading if its too high (0.35 for a TN-C-S) (0.80 for a TN-S) You may have a bad earth from the supply which would push Zs values up!Check earthing conductor tightness! if still high inform DNO! You can increase conductor size which would bring R1+R2 Values down therefore reducing Zs! Split the circuit into smaller circuits! iphonex mini