Electrical design guide

To answer my own question a - there are some limiting Ze values here: Earth fault loop impedance revision of ENA Engineering Recommendation P23 e.g. 90% of 100A supplies will have a supply impedance ≤ (0.25+j0.23)Ω

   - Andy.

To answer my own question a - there are some limiting Ze values here: Earth fault loop impedance revision of ENA Engineering Recommendation P23 e.g. 90% of 100A supplies will have a supply impedance ≤ (0.25+j0.23)Ω

   - Andy.

the resultant of that of course is sqrt (.25^2 + .23^2)  or about 0.34 ohms, and at a touch off  45 degrees. (it would have been be 45 degrees if the two were exactly equal.)

Mike

which if I remember my O-level trig correctly means we can equally write it as:

0.3397 = cos(42.614º)*0.25 + sin(42.614º)*0.23

(perhaps slightly perverse in the immediate context, but might compare with the appendix 4 approach)

   - Andy.

yes, the appendix 4 seems to go out of its way to avoid mentioning complex phase, which is for me at least, a much easier way to visualise it.

M.