At 12 volts, the size of the cable must be large. Even if the current is only 15 amps,
it is advisable to use a heavy cable. For a distance of 20 metres, the recommended
size is 6 mm2 (10AWG). The diameter (thickness) of each copper wire is about 3mm.
A 15 amps current flowing in this cable will lose 15% of the power from the wind
generator as heat in the cable. If the cable is longer, it should be heavier, in direct
proportion.
Electrical Safety
There is no danger of electric shock from a 12 volt battery. But if the wind
generator is disconnected from the battery, and running fast, then the voltage will
be higher than 12 volts, maybe as high as 50 volts. Do not run the PMG at high speed
without a battery connected.
The battery contains stored electrical energy. When there is a short-circuit fault in
the wiring from the battery, for example the positive and negative wires touching
each other, this energy is released in a very high current. The cable will heat up and
burn. Therefore it is necessary to use a fuse or a circuit breaker on every wire
which attaches to the battery positive terminal. Use one fuse for the wind generator
and a separate one for the cable to the load (the lights, or whatever uses the power).
See diagram 50.
50. CONNECTING THE BATTERY
CABLE FROM
WIND
GENERATOR
FUSES OR
CIRCUIT
BREAKERS
CABLE TO
LOADS
-
12 VOLT BATTERY
+
DO NOT USE 'CROCODILE CLIPS'
FOR PERMANENT CONNECTIONS
PMG manual
page 47
June 2001