Again, thanks so much for your help, I thought I was gonna go mad as my tutor just finds it funny that it’s driving me crazy so throws bits in to confuse me 😪 now I can do I* X 0.1 / K? What’s that 0.95? Is this a factor for something?
This is exactly what I spoke to my tutor about, so the t=k2 X S2 / I2 calc is the maximum time the line conductor can withstand the fault for? is this correct?
I feel so dumb right now
So I just use the rule of thumb rule then? I initially done the calc using 1.5mm/1.5mm but as this was also coming out high I went around in circles with it. I just assumed i was doing something wrong and was afraid I was going to get "dumbed". Like i say ive followed the rest of the calcs the...
Yeah using adiabatic I’ve done the adiabatic with the Isc for R1+R2 1mm/1mm
1mm/1.5mm
1.5mm/1.5mm
all came out higher than the line csa. All other calcs I’ve done have been ok.
k=115
Right so not 0.2s like I was informed 👍 even using 0.4s disconnection time my cpc is coming out larger than line conductor in the adiabatic even when stepping up the R1+R2 values given in I3 OSG 😪
Thanks so much for your replies btw!!! This has been causing me grief, making me feel like I...
Full cable calcs for the above circuit 😪 I’m lost as I’m being fed cross information. I thought for the adiabatic equation you have to work out
1) fault current 230/Zs
2) disconnection time t= K*XS*/I*
This is my headache, my tutor has said that disconnection time should be taken as 0.2 as it’s 3ph which I questioned as it’ll be the line voltage surely. The problem is every time i increase line size R1+R2 values to say 1.5/1.5 which I thought would be sufficient my cpc size is still coming out...