Recent content by msb2003

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  1. msb2003

    City And Guilds 2365 Level 3

    Both EAL and C&G qualifications are of equal standing with the QCF standards. This means you should be able to carry on to the level 3 as Mikel stated (you may need to do a `bridging assignment` to cover topics not included in both qualifications though). I work in a college where we are...
  2. msb2003

    Rcds Or Rcbos?

    Sidewinder references for my previous coments, I did assume a domestic installation as upstairs and downstairs mentioned (possibly as mistake to make the assumption) Regulation 314.2- Separate circuits shall be provided for parts of the installation which need to be separately controlled, in...
  3. msb2003

    Rcds Or Rcbos?

    Ok, if sockets are undersupervision or clearly labeled for use of a specific piece of equipment you are correct they do not need to be RCD protected but instead of your smart arse remark, why not share your superior knowledge in the first place?! Fozzy, I hope my comments did not confuse you...
  4. msb2003

    Rcds Or Rcbos?

    Regulation 314.2 (often ignored!) states "Separate circuits shall be provided for parts of the installation which need to be separately controlled, in such a way that those circuits are not affected by the failure of other circuits" therefore a split board where 1 or 2 RCD`s cover numerous...
  5. msb2003

    How Fast Should A Fuse Trip If Cannot Let Go?

    Thanks Canoeboy, why couldn`t I do that !!?? ; -)
  6. msb2003

    How Fast Should A Fuse Trip If Cannot Let Go?

    Forum won`t let me insert the image!!! When you think about it, it is only what we do with TT circuits, as we cannot achieve the Zs values due to the high Ze path of the Stake and general mass of earth. Values are calculated to ensure touch voltage does not exceed 50V eg 50V / 30mA = 1667...
  7. msb2003

    How Fast Should A Fuse Trip If Cannot Let Go?

    Regulation 411.4.9 - Where an RCD is used to satisfy the requirements of regulation 411.3.2.2 the maximum values of earth fault loop impedance in Table 41.5 may be applied for non-delayed RCD`s Regulation 411.3.2.2 gives disconnection times and table 41.5 gives maximum earth fault loop...
  8. msb2003

    How Fast Should A Fuse Trip If Cannot Let Go?

    The regulations do specify 0.4 sec and 5 sec respectively, for TN systems and 0.2 and 1 sec for TT systems (don`t forget distribution circuits are the same as circuits >32A) however your comment I`ve highlighted that they will always disconnect in these times is incorrect. These are the...
  9. msb2003

    How Fast Should A Fuse Trip If Cannot Let Go?

    Thank you Wozz for clearing that up before I got back to reply. If anyone wants to check the OSG they will see BS 4293 listed whereas all new RCD`s are BSEN 61008 or RCBO`s BSEN 61009. For some reason (beyond me) the older RCD`s must operated 100msec quicker, although how often do they ever get...
  10. msb2003

    How Fast Should A Fuse Trip If Cannot Let Go?

    For circuit breakers to disconnect in 0.4 sec (requirements of a TN system) a `B` type needs 3-5 times it rating to flow, a `C` type needs 10x and a `D` type 20x. So as other members have correctly said, by the time this amount is flowing you`ve had it!! 50-80 mA is the figure quote as the...
  11. msb2003

    Connections Mag - Issue 185 - Big Mistake, Methinks

    The NICEIC published this some time ago and at the time I though it strange. I work in a college so checked with a senior lecturer and we agreed that while it technically may be allowed to use the green/yellow of a multicore cable, it is not good practice. The regs do say the green/yellow should...
  12. msb2003

    Level 3 2330, 303 Written Exam

    303 written is mainly about fault finding and an extension of the 302(papers set by C&G). The 301 is a Gola exam and is 50% H&S and 50% principles. The 302 and 303 practical exams shouldn`t take long (1/2 day for both) and are testing and fault finding. Good luck
  13. msb2003

    Lighting circuit tripping RCD

    Reg 314.2 is the one you want. Not got it here but something along the lines of, "The operation of one protective device should not effect another cicuit and due account of its operation taken into account" Strictly speaking, one RCD and 4 MCB's for example fed through it does not comply to...
  14. msb2003

    10th feb 2391 exam

    Calculation wouldn't include parallel paths your correct, but they would reduced the Zs!!
  15. msb2003

    10mm swa

    I agree that you may have been mislead, you apply the 0.8 or 1.2 factors when calculating R1+R2 values, not on the current carrying capacity
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