Your article on electrical wiring in Costa Rica was of great interest to me. I am an electrical engineer and am somewhat fascinated by the fact that most Costa Rican’s seem to consider themselves experts in electrical wiring. This can be dangerous as you point out. It’s good that most of the homes here are made from concrete blocks.
Anyway I wanted to point out a couple of things people should realize when wiring or having their houses wired. First of all AC and DC wiring is totally different. AC has a neutral and a ground, whereas DC has only a ground. Do not wire your house unless you understand the difference.
The second thing is that fires are not caused by electrical shorts. A short is where the hot wire in the circuit is accidentally connected to ground (short). This situation will either blow the fuse, trip the circuit breaker, or burn up the wire almost immediately if neither is present.
Fires are generally caused where current is flowing in wires where you want the current to flow. But if you have a point of resistance in the circuit, such as a nail used as a splice or a bad connection, this tends to heat up and many times causes a fire before the connection burns in two. The circuit breaker will not trip because current is supposed to be flowing through the connection.
Guy C. Moats
Playas del Coco