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values

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  1. J

    BS7671 Amendment 1 EICR Form

    In amendment 1 of BS 7671 the BS1361 cartridge fuse is being replaced with the new BS88-3 fuse as part of over 700 changes. Another change is the replacement of the PIR form with the EICR form. My question is that after 1st January 2012 on the new EICR what version of BS7671 would have to be...
  2. T

    Earth fault loop impedance readings through a UPS supply

    Does anyone have any experience in recording values of EFLI on circuits fed through a DB supplied via a UPS please? The meter shows the above scale arrow. I understand that there will be no reference to the external earth due to the inverter inside the UPS but what will happen to the UPS...
  3. K

    DNO and Ze values

    Greetings, ENW are now quoting figures of 0.8 for the maximum value for tncs (or pme, whichever you prefer.) Our company have always reported high Ze figures directly from the property, (no different to anyone else in the same position)and UU have always responded to high readings, but since ENW...
  4. 0

    "Comment on the measured values obtained" <<<< Can you help me please?

    Hi, above is a picture of some measurements I have taken, and there is a task underneath it that asks me to "Comment on the measured values obtained". I'm not really sure WHAT it is I have to comment on, could someone help me out please? Thanks a lot. :)
  5. B

    Adjustable breakers

    In the case of adjustable breakers which value goes in the column for protective device i.e. if it a a 200a breaker and it has been tuned down to 180a?
  6. V

    2391 exam question on max Zs values

    Hi guys just looking at some 2391 exam papers and came accross this question could someone help me on this as to how to work it out many thanks. Refer to the measured values, tabulated below. Circuit 1 2 3 4 5 6 7 8 Measured Zs 0.8 1.1 1.3 6.2 5.1 2 0.6 1.3 Calculate...
  7. C

    Maximum Ze Values

    Ze values on; TNCS TT TNS
  8. B

    Quick Question - Max Permitted Zs Values

    On an Installation Cert in the 'Max Permitted Zs' column should i put the tabulated values in the regs or should i put the corrected values(x0.8 rule of thumb)???? My guess would be corrected values as that would be max zs at ambient temperature at the time of test? Cheers peeps, Dan:cool:
  9. R

    NICEIC Certification Scheme NICEIC DI Assesment

    Afternoon guys, I thought id come on here and see if you have any more information what will be needed from me in my first assesment, iv read all the leaflets they send out, but just thought id ask as many of you as you have been having assesment for years and those who have recentley just...
  10. G

    Maximum Zs values and the rule of thumb

    Hello, can someone explain to me the 'rule of thumb figure' (0.8) when calculating max Zs value's from BS7671!? Currently doing a PIR in a foundry where i measured the ambient temperature at 21 degrees at ground level, i bet you can add another 10 degree's higher up ...and that's on a good day...
  11. johnboy6083

    Installation of earth rods

    Having just read some posts regarding Ra values of an earth rod, and some disagreement of the values to obtain, i thought i would post a little guide. Earthing Design Considerations
  12. M

    Resistance Diameter Values

    hi if someone has a minute of thier time to help me out with this solution i would be most grateful? Question: A length of circular section of conductor has a resistance of 2 OHMS. If its diameter was doubled what would its Resistance be ? answer 0.5 i thought the answer would be 1 but the...
  13. T

    Zs, R1+R2 Measured Values?

    When testing its always been said that its important to take your Continuity reading (R1+R2) and that Zs can be calculated (avoiding working live) So how many of you do all your correct R1+R2 values and then claculate there Zs and put this figure down on your test sheets? Or are most of you...
  14. S

    RCD throwing Zs readings off

    installed a new dual rcd cu today and on completeing my tests I noticed the zs values were slightly above the max permitted by bs7671. All my other readings, r1+r2s ect were fine and the ze was 0.2 off the top of my head. took a zs reading off the load side of both rcds and both values came...
  15. Amp David

    Max Zs values for BS88 types gM

    Can anyone point me in the right directions for the values please. Thankyou :p
  16. Amp David

    Resistance of cable values in BRB

    Can anyone point me to where in the regs it gives values for the resistance of cables.
  17. Johnuk

    hello all i got a question on a testing question

    am looking at the question and am a bet lost now on answering it..... The maximum permissible values of earth fault loop impedance for three circuits are 1.44 Ω, 0.92 Ω and 7.67 Ω. If the measured values for these circuits are 1.25 Ω, 0.68 Ω and 6.22 Ω, determine if the measured values are...
  18. T

    Voltage drop help please!

    Hi, i am confused about how voltage drop is worked out and need an answer for the following please; Work out cable size and cpc size you need when you have: Cable length = 50 metres Ib = 32Amps to get a voltage drop that complies with regs i.e. below 5%(11.5 Volts). It's wired in singles and...
  19. P

    Zs Values.

    Hi Guys. Just a quick one, How do you measure Zs values on a lighting circuit which has no CPC's. Thanks guys.
  20. P

    Zs values on TT system

    Hi guys new to testing and about to do my first TT system tomorrow. Popped in today and did a quick Ze test and got 16.98 ohms. Zs values will not meet max values for 7671. Whats your thoughts guys. (what have I forgotten?). Pete

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