DC Fuse Selector

Why not size the fuse to the device rating?

DC fuses in vans primarily protect **wiring** from overcurrent and fire risk. Device ratings can be lower or higher than safe cable limits. Always confirm the fuse **does not exceed cable ampacity**; then ensure it still supports normal operation without nuisance blows.

How do I pick continuous vs intermittent duty?

If the circuit can run **for minutes or longer** at a steady draw (fridge compressor cycles, fans, pumps on for >3 min), treat it as **continuous** and apply ~**125%**. Short, infrequent surges (valves, small actuators) can be **intermittent** at ~**100%**, provided the fuse’s time-current curve can ride through brief peaks.

My target fuse is larger than the cable allows—what now?

You have two safe options: **increase cable size** and re-evaluate, or **reduce the circuit current** (smaller load, current-limited controller). Do **not** install a fuse that exceeds cable ampacity.

Which family should I use: ANL, MEGA/MIDI, or ATO?

- **ATO/ATC (blade)**: small branches up to ~30–40 A. - **MEGA/MIDI**: robust mid-range (30–300 A), great near batteries and busbars. - **ANL**: high-current mains (50–400 A), common for inverters and main feeds. Match the **holder** to the chosen family and environment (heat, vibration, ingress).

Where exactly should I mount the fuse?

As **close to the energy source** as practical (battery or distribution bus). Typical guidance is within **15–20 cm** of the positive post/bus, considering service loops and safe mounting.