<snip>.............Size the breaker or fuse to protect the wire size it is connected to and be sure you sized the wire for the current draw on it.
Sorry guys but I must be missing something here. Surely you should be providing fuse protection for the load and not the wiring. Since the former should always be considerably less than the wire rating, are you not protecting both. I would rather protect my avionics with their lower current raw and thus have the wiring covered by default. One might even argue that the unit itself (radio or bulb etc) could otherwise act as a fuse in its own right (God forbid) in an extreme event and blow before the fuse you've used to protect the wiring. In critical ignition/fuel pump circuits you would need to plan conservatively for an initial inductive current that is higher than the running current and choose a higher rated or slow blow fuse. I am using two 15 amp self resetting circuit breakers for this job in an independent switchable duplicate system even though each ignitioncoil/fuel pump combination only draws about 5 amps in toto. No problems so far...touch wood!! John PS: Regarding low and slow training. There is apparently an article in EAA Sport Aviation Dec 2003, pages 110-112. Has anyone seen it? The Martindale Family 29 Jane Circuit TOORMINA NSW 2452 AUSTRALIA phone: 61 2 66584767 email: johnj...@chc.net.au
