>>the Main circuit breaker keeps popping within a couple minutes of turning the alternator switch on. The Main circuit carries the entire aircraft load on battery, but shortly after turning the alternator on, it pops, even when everything else is turned off.<<
This should not be true. There is no "main circuit breaker". The circuit breaker you are most likely referring to is the generator breaker (originally a fuse). It carries the charging current from the generator to the battery but should not be in the circuit from the battery to any of the accessories. It should be between the generator output and the main buss. (Otherwise the aircraft load could never exceed the generator output capacity.) If it is blowing it is either faulty or the charging current is exceeding the breaker rating. If you have upgraded to an alternator it may simply be too small. You might get away with it as long as the battery is charged, but if the charge is low the alternator output can exceed the original 30 amp rating. John Cooper Skyport Services www.skyportservices.net
