equation

equation

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  1. J

    What equation can be used here to find the value of the capacitor?

    Hi all, I'm struggling with these questions for this circuit as the equations I have in order to work out impedance etc all seem to need the value of the capacitor so I'm at a loss now and was wondering if there was a way to work out the capacitor value or if there was another equation I could...
  2. J

    Need help with one of my questions

    Any can help where I’ve gone wrong?8
  3. S

    Help with Ring Tabulated Current Equation

    Hi there I am struggling with the following calculation. 4mm Ring Final Circuit, In = 32A Cg - group of 6 with a correction factor of 0.57 Ci - 50mm insulation of 0.78 It = In/CgCi It = 32/0.57x0.78 It = 71.97A Then I get stuck here: Ib < In < It < Iz 4mm Cable from Table 4E2A gives Iz of...
  4. S

    Adiabatic Equation help

    Hi was wondering if im doing this right. The question in: Determine for a chosen circuit "the minimum possible csa of cpc which will satisfy the requirements disconnection as ADS under earth fault conditions and the adiabatic equation as reg 543.1.3." Circuit: Single core pvc 70* 2.5mm2 +...
  5. B

    Could anyone please help me with this adiabatic equation?

    Hi, and thank you to anyone who's taking the time to read my question. i'm struggling with the outcome of an adiabatic equation i'm doing and would be incredibly grateful of any guidance or help anyone could offer. its for a design project and i'd like to know if i'm doing something wrong...
  6. spud1

    Adiabatic equation help

    Hi guys, I had a brain fog on the adiabatic. Trying to ascertain suitability of a 6mm bonding conductor in a domestic installation. Doesn't help that I forgot my regs book too! I have a pefc of 1.17KA. Can anyone help please? Thanks.
  7. W

    I need help with figuring out an equation

    Hello, I’m in dire need of help. here is the question A kitchen Ring final circuit is wired in 2.5/1.5mm T&E and protected by a 32A type B circuit breaker. 70m of cable has been used. Q1. What is the expected r1, r2, rn value ? So far I’ve used the equation R=Mohms/m X Length =1,365.7...
  8. B

    Adiabatic Equation

    Hi All, I think I have confused myself somehow and feel I am spiraling into further confusion. When I am doing the equation, it is saying the longer the cable is, the smaller the CPC has to be. My calculations are below. 20A radial BS61009-1 Curve C Install method type B using 2.5 singles...
  9. C

    Adiabatic Equation - why only for CPC?

    Why adiabatic equation is used only for sizing of CPC? Why not for phase conductors too?; As the fault current also flows through the phase conductors
  10. S

    Earthing equation 3P 100A

    Hi guys I carried out an EICR a while back on a property with 3P 100A incomer and it only had a 16mm earth. I thought this was undersized, I made contact with the local DNO and had 2 replies, one said it was fine, the other said it should be 25mm. Im trying to do the adiabatic equation for it...
  11. S

    Help with Adiabatic equation

    Hi, Could anyone check my calculation please. Protective device 60A 1361 E.S = TN-C-S Cable 16mm T & E CPC 6.0mm Zdb = 0.43ohms Multiplier temp 1.20 0.43 x 1.20 = 0.52ohms 230/0.52 = 442A SR 442 squared x 2secs/115 = 5.43mm Cheers
  12. Zdb

    Adiabatic equation infinite loop

    So I'm looking into the thermal constraints of every cable in my 2396 project. I've used the adiabatic equation in a spread sheet and 99% of them are fine with the CPC I have selected. However, there are a few really short circuits with very low earth fault loop impedance. Because of this the...
  13. Michaelwgroves

    Using adiabatic equation for CPC on SWA

    I want to use the armour as my CPC but need to check it complies. The cable will be run from a SP Distribution panel to CU. As per Selection and Erection Guidance Note 1 table D10a I can see a 10mm XLPE SWA requires a 31.1mm csa to comply, but only has 26mm on 2-core. 20171231_114229828_iOS.jpg...
  14. M

    Adiabatic equation on distribution circuits

    Now I know this has probably been covered a few times but I'm struggling to come to terms with my own calculations. I would appreciate it if someone could tell me if my calculations are correct. So basically I've done a periodic and some of the CPC sizes for sub mains are less than half the...
  15. A

    adiabatic equation help!

    Hi guys, really need help to solve this question i have on my assignment for my apprenticeship not asking for the answers but for guidance page numbers etc Basically after cable cals i got 4mm2 for live conductors for one of the circuits they wanted me to work out and it is a 36m length run...
  16. Z

    Verifying SWA CPC suitability disconnection times / adiabatic equation

    As you may know looking at some of my posts I've been thrown back in the deep end recently – and don’t have much experience with complicated calculations. As this is the first time I've used SWA to go from the main supply to the primary CCU, and as I'm using the steel armour as my CPC, rather...
  17. U

    adiabatic equation a lot of questions.

    Good evening everyone, I'm doing 04A1 practical assessment at the moment, and I'm confused with adiabatic equation. It seems easy when tutor is around, but when you're trying to sort it out on your own, a lot of questions appears) I would really appreciate if you could help me out. Here is one...
  18. N

    Voltage Drop Equation

    Hi, I've been doing some revison and came across 2 different equations for voltage drop. The first one is; Vd = mV/A x Ib x L divided by 1000 The second one is; Vd = (R1 + R2) x Ib x Multiplier The multiplier is to compensate the difference in conductor temperature at the time of the test...
  19. infinity

    Adiabatic equation

    Evening All, I have an industrial install this week, installing 200A feeds to MCCB panels in workshop, with 70mm SWA Im just working out the CPC at the DB, not done this for a while so just wanted to check it.. S= root(I2 X T) / K The fuses are BS88-2 200A, i have another DB in exactly the...
  20. S

    Adiabatic Equation APP to download on the mobile phone.

    Hello chaps, and indeed, chapettes, What do think o an Adiabatic Equation APP for the mobile phone? Does I take away any skills..?

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