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  1. T

    Grouping factors domestic

    Hi all question regarding grouping factors in a domestic house. is there still a need to apply grouping factor Calcs in a 3 bed domestic house hold, I mean do we apply grouping factors for going through joist holes,where there is say 9 cables going through a 32mm hole but length of grouping at...
  2. B

    Cable calculation - Derating factors

    This is my first time here so please go easy 😂 I am currently designing some circuits for large convenience store and I have a question about the thermal insulation derating factor. A radial circuit will feed two display fridges, total load 10A. The circuit will run from the DB through the roof...
  3. J

    Diversity Factors

    Hello people, I'm designing switchgear for a residential estate, of about 60 houses, specifically the protection for the incomer. Is there any provision in the British Standard that advises on diversity for such a large number of household units?
  4. R

    Long method de rating factors

    Having used Amtech for so long I can't remember if the de rating factors are applied to the design current or the tabulated regs current, can anyone give me a refresher example calc, I guess it has to be tabulated if it's a current reducing factor
  5. F

    Lighting correction factors.

    Now I know with discharge lighting you times by 1.8 but I was wondering what factor to use for high frequency (HF) ballasts and also LED lighting? Was thinking maybe 1.2 just to be safe?
  6. B

    Cable Factors for trunking

    Hi All, Anyone know the cable factor for 150mm LSF cables for installing in trunking? Table E5 in my OSG only goes up to 25mm!
  7. T

    Customer service from City Electrical Factors

    Just had a phone call. HELLO! I wait ARE YOU THERE! Who is this? say I I CANT TELL YOU WHO I AM I HAVE A SECRET CRUSH ON YOU Put the phone down Check the internet for who the number is, it is CEF. Call them and someone answers and like me finds it very weird. They say they will ask technical...
  8. D

    Derating Factors

    Hi guys, Might be a silly question but getting really confused. Table 4D5 for choosing cable size for different installation methods, does this already have de-rating factors applied for the different methods? If so, then if you calculated your current capacity using specific de-rating factors...
  9. 2

    Conduit runs over 10 meters

    Hi, as my name says im just trying to do the project on my 2396, im looking into my options of cable management and on route i have stumbled across conduit rating factors p142 yellow osg (ive never worked with conduit) and the rating factors only go up to 10m, is this 10m maximum length or 10m...
  10. C

    Galvanised Conduit in house conduit factors

    Hello. i've got a brick wall in my conservatory and ive painted it a color but left the bricks on show, currently the electrics for s/o and lighting are in shoddy plastic off cuts of mini trunking and exposed bits of old twin and earth. I was thinking of using Galvanised conduit and put it on...
  11. M

    T & E in conduit calculation help please

    Hi Guys, I apologise in advance as I have done this a**se about face, I have just finished putting power to my shed ( I am currently training to become a sparks got my 17th edition at pass in Watford shortly) and hoping to use my shed as my part p inspection as hoping to join ELECSA. Anyhow I...
  12. D

    Best GU10 LED bulbs?

    Hey everyone, just wondering what everyone thinks the best LED GU10 bulb is. Factors include: lux, spread, cost, lifespan, colour and size. Also which make of bulb is most equivalent to the 50watt halogen bulb including all the above factors.
  13. R

    Calculating voltage drop on larger SWA cables

    Hi All A question I've asked many a lecturer and none of them have come up with the same answer. When looking at the current carrying capacities for SWA cables, from about 35mm onwards you get an r, x, z value. What are these and which one do you use when carrying out voltage drop...
  14. G

    Hi all help wanted

    hi all new to this site and was wondering if anyone had the answers to junes 2391 exam paper,i attained a copy and was wanting to check my answers cheers
  15. G

    Shower cable sizing

    There seems to be a lot of ambiguity and difference of opinions on the Forum regarding shower cable sizing. I have one to fit, 9.7Kw through a seperate RCCB and 50a MCB shower unit via a Henley block using 16mm tails. @ 11m run - 6m capped trunking, 3m under floorboards and 2m clipped direct in...
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