CPC size help

[Guest123]

Page 243 isn't viewable....

Interestingly, it does show the use of the manufacturers I2t values in the adiabatic equation that I mentioned earlier.

Using this value is where the 1.2mm minimum value for CPC came from.

Definitely more than one way to skin a cat.

Sent from my BlackBerry 9800 using Tapatalk

 

[silverfox1]

According to table B7 page 120 0f onsite guide as long as using a 20A class 3 mcb a minimum size protective conductor of 1.5mm can be used if the fault current does not exceed 3KA, I suppose that producing this table the IET have taken account of all what has been disscussed in this thread I2t etc.

 

[pencilpusher]

and to tidy this thread up, I have added a link to an interesting thread which links in with this and class 3 MCB's and "Lenny" stars in this one too! I think I am getting to grips with design lark. Thank you to all. PP
:seeya:http://www.electriciansforums.net/e...cal-regulations/20007-adiabatic-equation.html

 

[silverfox1]

Found this page from BS 60898, appendix ZA with classification of circuit breakers into energy limiting classes,Lenny mentioned it in an earlier post hope you can make use of it.

View attachment Annex ZA 1.pdf