What diameter must a copper wire have if its resistance is to be the same as that of an equal length of aluminum wire with diameter 3.26mm?
It is very common in older homes to have tin coated copper wiring which many people then think they have aluminum wiring. If you have a piece of the older wiring or can turn the breaker off to one of these wires use a screw driver to scrape at the wire on the bare end; if it's tin coated copper you will see the orange/rust color of copper after a few light scrapes, the scaping is nothing agressive. This will determine if you have aluminum or not. Someone else mentioned about a loose connection which if a copper wire aluminum wire are connected together it would very likely fail creating a short. The two different materials expand contract at different rates which creates a bad connection. There is a special crimp process that can be done to join the two but a electrician should definately do this. A lot of the older homes just have two many items all on one breaker. With what you've described I would suggest using a electrician. Additional: If no breakers are tripped off and you do not have power in some areas you might have another panel (sub-panel) somewhere else in the home OR this circuit is hooked up to a GFI outlet somewhere else such as the kitchen, bathroom or garage. I would physically re-check each breaker and then hunt for a GFI outlet and sub-panel.
aluminum wire with diameter 3.26mm Resistance of a wire R = ρL/A ρ is resistivity of the material L is length in meters A is cross-sectional area in m? A = πr? resistivity Cu 17.2 (nΩ-m) resistivity Al 28.2 (nΩ-m) 1 = Al 2 = Cu ρ1L1/A1 = ρ2L2/A2 lengths are the same ρ1/A1 = ρ2/A2 ρ1/ρ2 = A1/A2 28.2/17.2 = π(1.68)?/πr? 28.2/17.2 = (1.68)?/r? r? = (1.68)?17.2/28.2 r? = 1.72 r = 1.31 d = 2.62 mm .
