fault calculation

[beaver74]

evening all

i have come a cross a bit of 6.00 T+E to day feeding a range cooker backed up with a 50A breaker which I will derate as when diversity calculated will be fine.but it accured to me I had forgot how to calculate if the 50A would be OK from the disconection times side of things (although it will be replaced

 

[Sintra]

Find out the maximum permissible Zs for the type of overcurrent protective device and compare to the measured Zs of the circuit.

 

[tony mc]

What sort of 50 A ocpd is it.

As a starting point I would be looking at tables 41.3 onwards and useing the rule of thumb (x 0.8) to see if the disconnection times can be met!

As you have mentioned start with the diversity which will bring the OCPD down!

I don't understand the Bit of 6.00 T+E mind you !!!!