values

  1. C

    UK Why don't values in the OSG table I1 match those calculated?

    Hi everyone. I am really puzzled by this, but I suppose there is an obvious answer / reason! Anyway, Table I1 in the OSG says the mΩ/m value for copper with a CSA of 25mm2 is 0.727. However, when I calculate the R value using the formula: I get 0.688... Does anyone know why the values aren't...
  2. S

    Continuity values keeps going down.

    So bought a second hand Megger BM233 to practice with as I'm a college student.. So I was just using it on a loose 2.5 cable. Testing on the neutral from both sides . Whilst having the device on the Ohm side. I nulled it to zero by touching the probes. When I do the dead test. It starts off...
  3. J

    Zs Values for BUSSMANN - ED355 FUSE BS88 355A 415VAC

    Hi All, Can anyone help with calculating a Zs value for the fuse described in the title. The fuse sizes in Fig 3A3(c) of the 18th edition wiring regulations do not have a 355A fuse and jumps from 315A fuse to 400A fuse. I've searched and searched but struggling to find an answer. Any help is...
  4. U

    Do I use zdb or ze when calculating zs values on am2?

    Got my am2 coming up on Tuesday and I know I have to calculate my Zs readings Maybe I’m overthinking this but am not sure if I need to use the Ze (which is apparently given to me) or my measured Zdb from my three phase panel in the equation. I have heard different answers, would be great if...
  5. Q

    Merlin Gerin MCCB Zs Values

    Hi All, We have a Merlin Gerin Compact NS100N Single Phase MCCB I've been asked to find its Max ZS Values and to be honest I cant find anything! This is an from an old MCCB board we are re testing. I put it in google and cant seem to find anything, I know Schneider bought this brand out. But...
  6. Simon-0116

    Cable calcs zs and ze values

    Cable calcs using cable calc app Working out cable size for a workshop. 100m long, 100a supply, mccb 100a zs- 0.23 ohms, in a duct on its own, tt earth on 300ma rcd.- 20 ohms App says 50mm swa which I expect. But if I alter earthing to tncs 0.35 ohms it says max ze exceeded zs of device...
  7. M

    help with max zs values please

    hello , can anyone reccomend a free download for max zs values for bs 3871 ct breakers please
  8. O

    UK Max zs Values in the on-suite guide

    Hi all, Just wondering if anyone can shed some light on the max zs values in the OSG, they don’t seem to follow the 1.25 divisor stated in the note on page 126 For example BS 60898 circuit breaker, max zs at 70 degrees is 7.28, following the formula this should be 5.82 at 10 degrees which is...
  9. S

    Vw electrical vacuum control valve n75 - Ohm values

    What is a correct Ohms value for n75 valve on vw 1.9 TDI, 96kw engine? I have like 16 Ohms but if I am not misunderstood on spec it says more than that. Does it mean my valve has malfunction? I checked almost everything else but my car still has delayed boost.
  10. T

    LED resistor values.

    Hi, I am just wondering if you can please help me. I have four LEDs connected to a 9 volt battery. They have little circuit boards in them. They will run between 9 volts and 15 volts. I have them wired up in parallel to a 9 volt battery. They work fine. They are drawing 30mA at 9 volts. So I...
  11. Rockingit

    Z values for fuse to EN60269

    Anyone know if there is a specific list of Z(s) values for a fuse to EN60269? I've just used 5s values for an 88:2 as I figured they'd be pretty close but wondered if there is an actual table anywhere. No biggee. Alternatively, has 60269 been replaced by another standard anyway?
  12. K

    Strange voltage and power factor values and installation issues

    Hi, We have installed 2 meters (each meter is a 3 phase meter) for sub-metering in a residential house (1 phase installation per apartment). One of the meters, after correcting installation, works fine now. The other one, in my opinion measures strange voltage values. We had since the begining...
  13. P

    Zack values

    Hi I was wondering if anyone could help me , I was trying to find the maximum Xs value for breakers 60947-2 and 60947-3 . Does anyone know we’re I can find this information ?
  14. G

    typical earth leakage values

    hi all, If there is such a thing as 'typical' values, what, in your experience would you consider these to be from equipment such as pc's and other IT, washing machines and any other significant sources? thanks
  15. KennyKen

    What’s your countries Max Zs Values?

    I’m intrigued to see the differences in Max Zs values compared with the 18th & NEC
  16. newfutile

    Maximum ZS values GN3

    On page 142 of the latest Guidance Note 3 it list a 16 amp type B max ZS as 2.15, however i think 2.2 is the real value, it also states that at 16 amp type C is 1.1 ohms which is correct, but a type B should be double the value of a type C. anyone else have a view on this?
  17. D

    Max zs values

    Hey all im just trying to learn max zs values from a NICEIC chart i have, now learning these values isnt a problem but the sections reffering to bs3036 fuses and type D mcbs both have two lists of readings - one each for 0.4s and 5s trip times - where as the sections for type B and C only have...
  18. J

    Zs values and 50v

    Hi all I’m doing some work on my NVQ and came across this on the internet. Can someone explain this picture to me and if it is correct.
  19. Baddegg

    Max permitted Zs values...

    Anyone know where I can find max Zs values for these?.....and the 6a LN 5906....
  20. A

    Zs values when there is additional RCD protection

    Hi everyone, Consider we have an RCD+MCB protection for a circuit. if we follow the tables for Zs values of a 10A, MCB, type C, the maximum value shall be 1.75 Ohm, this happens when 100A current flows ( as per MCB breaking curve). When the RCD disconnects the circuit in much less current, why...

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