tuesdays 2391 20 question

[SirKit Breaker]

S=6mm
K=115
I=240A
duration time t = (S² * k²)/I²
=8.3s

My money is on widdler

So is mine, he teaches it, and he knows his stuff.

Cheers........Howard

 

[Sparky Ninja]

the question didnt state that the conductor was bunched. i thought it best to assume not or it would have said.

The question is a 'thermal withstand' question, and not a 'size of cpc' question, so table 43.1 would be used.

We should never make assumptions when looking at these questions, all the information we need is in there.

 

[gamblor6]

ok fair enough, great this place!

 

[gamblor6]

had a look at 43.1, your right mate.