Question on Multiple 12V Battery Connections
I have multiple connections I'm trying to make on my positive battery terminal. If I include the two connections the RV manufacturer made, the solar connections, inverter connections, and possibly ot...
Forum Discussion
There's no need to fuse the negative lead of the batteries. Just connect them to the chassis ground system with a connection capable of carrying the net sum of any possible battery current. In simplest terms, this means use the same size wire for the negative ground connection as for the positive connection to the bus bar. (Generally there's also no need to have a great many connections to the negative battery pole.)
An overcurrent protection should be used whenever you have a source that could supply more current than the following wire can safely carry. Typically, with a bus bar, this would mean a large main fuse or breaker close to the battery (for these sorts of things, the battery is generally assumed to be able to provide infinite instantaneous current...which is a bit of a simplification), and then individual fuses or circuit breakers suitably sized for the wires and loads that connect to the bus bar.
Arguably, one possible exception to this general rule for fusing might be the breakaway trailer brake system, if applicable. That sometimes is run unfused, on the theory that it is safer to have the brakes unable to be defeated by a blown fuse than to have the safety from fires caused by short circuits that a fuse provides. I've seen pictures where this is done in either way, though I personally would prefer it with a fuse or circuit breaker.
An overcurrent protection should be used whenever you have a source that could supply more current than the following wire can safely carry. Typically, with a bus bar, this would mean a large main fuse or breaker close to the battery (for these sorts of things, the battery is generally assumed to be able to provide infinite instantaneous current...which is a bit of a simplification), and then individual fuses or circuit breakers suitably sized for the wires and loads that connect to the bus bar.
Arguably, one possible exception to this general rule for fusing might be the breakaway trailer brake system, if applicable. That sometimes is run unfused, on the theory that it is safer to have the brakes unable to be defeated by a blown fuse than to have the safety from fires caused by short circuits that a fuse provides. I've seen pictures where this is done in either way, though I personally would prefer it with a fuse or circuit breaker.
