With reference to 433.1.204 and cable as installed has min capacity of 20A if protected by a 30A or 32A. If the protective device is reduced to 20A how is the new minimum as installed capacity calculated or arrived at ? I've been looking in the Electrical Installation Design Guide, but the answer is avoiding my eyes.
Hi Mike, in your example the leg carrying 27A would be running hot, perhaps 70 deg C, therefore would have higher resistivity than the cooler longer leg. I can't do the maths but would this make a huge difference?
Now there's a thing. The ring could be self current regulating. The short hot insulated overloaded length has an increase in electrical resistance so the supply shifts to the longer leg.
Hi Mike, in your example the leg carrying 27A would be running hot, perhaps 70 deg C, therefore would have higher resistivity than the cooler longer leg. I can't do the maths but would this make a huge difference?
Now there's a thing. The ring could be self current regulating. The short hot insulated overloaded length has an increase in electrical resistance so the supply shifts to the longer leg.
