Q&A: Fuses

Q&A:  Fuses on a 12V system

Q: Do I really need fuses on my 12V system?

A. Yes. Low-voltage DC systems tend to be a bit safer for users than jittery AC, but your battery is close by and it’s full of electrons just itching for someplace to go. It can deliver many more amperes into an accidental short circuit than a miles-long AC system. This leads to burning insulation dripping off red-hot wires and other unpleasant things. Hence, our #1 safety rule: Any wire attached to a battery must be fused! Legally, every wire circuit should have a fuse or circuit breaker that’s sized to protect the smallest wire in that circuit. DC load centers, or fuseboxes, or even single inline fuse holders do this. Sometimes with really small systems we just put a 30A fuseblock at the battery positive terminal to cover everything.