Originally Posted by btrayfors
Well, yes and no. Although we may be splitting hairs a bit here, please read the following statement from Blue Sea Systems regarding selection of their ANL fuses (bolding mine):
"Because ANL fuses behave differently than all other circuit protection devices, that is, their blow point value ranges from 140 to 266% of nominal value, the 80% rule doesn't work. It is necessary to use a different procedure to select a suitable ANL fuse. To choose a suitable ANL fuse, refer to the ANL Fuse Blow Point table above. According to the table, a 100A ANL fuse has a blow point of 175A. Therefore, a 100A ANL provides suitable protection for the 4 gauge AWG circuit in this example."
This is particularly relevant to the smaller ANL sizes, where the blowpoint -- after 8 minutes -- can be as much as 266% of the nominal rating.
I suspect that statement is not for short circuit protection which is what the ABYC E-11 ampacity table deals with.. Can you post a link to that?
What is the 80% rule they are referring to? When posted out of context with the rest of it sometimes it's hard to decipher that statement.
If you look at Blue Seas own short circuit protection suggestions they are not following their own advice, and that is why I suspect that statement is for device protection not short circuit..
Gotta run off to replace more dead three year old Lifeline's....