earth fault loop impedance calculation

[nathanm1982]

hello all could anyone help me i am doing my 2392 and i am a little stuck i have been asked a question which is using the following measured value of loop impedance 0.5 (40amp bs en 60898 type b mcb) ferfering to the maxium tabulated value given 1.15 show by calculation if the measured value is acceptable what would be the calculation thanks

 

[Zdb]

Are you sure that's how the question is worded?

Ferfering?

 

[nathanm1982]

Refering

 

[Deleted member 105166]

0.50Ω/80%=0.625Ω
0.625Ω<1.09Ω (Table 41.3)