Hi Baobab, The Alt CB protects the output of the Alternator (60A.), and the Alt Field CB protects the Alt Field current of say 2 Amps.
I think you are confusing the role of the Regulator... This only has control of the field current (max 2 Amps.) So is only handling very small currents.
The Alternator current does not go anywhere near the regulator!
The output of the Alternator is capable of many Amps, and could be wired with thicker wire.
The highest current on the aircraft is the Starter current, maybe 300 Amps, and as such requires a very thick cable.
It could be interesting if you could colour-code your diagram with the size of wires/cables used. So for instance the Battery to Battery Contactor, to Starter Contactor, to Starter, should be in thick cable.
Also the Ground Service Plug to Reverse Polarity Contactor to Battery Contactor can carry this Starter Current.
Pete
Last edited by phiggsbroadband; 18th September 2012 at 13:44.