4 square meters of wire, copper wire or copper bar good?
The main advantage of copper bars is that the strength is relatively high, for example, the vacant place is more suitable. If placed in the wall, personally feel that the copper wire is good, the same number of square wire, the more you can pass through the safety of the current is also greater. Another advantage is that it is convenient to install a socket or switch.
A little copper bar, you can replace the two air-conditioning
Copper is good, and now appliances are much higher power, safety is important
