In this screen we can see the "average" starting load was 286A. This was measured on a day when the air temp was 20F and the batteries in the bilge were at 32F. As such these currents were slightly higher than they normally would be on a typical small sailboat AUX motor.


Question: "How does a 300A fuse deal with an average starting current of 286A and not trip? Don't you want to always be under 80% of the fuses rated trip point?"

The secret is in the duration. This engine starts, from a loaded starter to unloaded, in just 0.75 seconds, as evidenced by the; "TIME 765mS".


If you look back at the trip delay curves for an ANL you'll see why this 300A ANL fuse has never blown despite over 1000+ starts on this engine since the installation.