Fuses on the panel, or not

A couple of comments about circuit protection some of which has been covered before in other threads;

- Pete Purdie's comment above about undersized wiring is on target. Bigger is better (within reason)! If you saw smoke you probably do not have Tefzel wiring. Get some!
- Fuses are great as they are cheap, fast acting and have ZERO voltage drop across its terminals. Cons are that they are more difficult to replace in flight and somewhat fragile (glass type).
- Breakers are great as they are easy to reset in flight. Cons are that they are expensive, somewhat slow acting and will cause a voltage drop across its terminals. This voltage drop effect is worse at small breaker values, you can loose 1/2 volt or more. That is fine for ships with generators but lousy for gliders.
- Put a FUSE on each battery at the terminals. This is the absolute minimum circuit protection you MUST have.

So if you really want separate protection for each of your devices, then use small value fuses rated just above the maximum current for each piece of hardware. Otherwise go with a large value single breaker to protect the entire system.

As to the use of different types of fuses (glass versus blade type) this relates more to what your IA will sign off. Blade type are certainly more robust and I saw them in lots of experimental airplanes at Oshkosh. But the FAA is a strange and demanding mistress. ;-)

My $0.02. Good luck.

- John