Sounds like we have similar set ups. I have two sets of 6V GCB midships and a third set of 6V GCB in the fwd bilge
. Normally all are connected in parallel but each set has a battery switch for isolation. The two midships sets feed a one/ two/ both switch and the battery switch common feeds a home made high amp fuse distribution block. In this common feed is a 250 Amp Class T fuse right at the battery switch. All the individual feed fuses for various systems are type ANL.
4- 6V GCBs are pushing the interrupt rating of the ANL fuses so the Class T in series solves (hopefully) the high current interrupt situation. The fwd bank is connected to the high amp fuse block with ANL fuses on each end. The fwd bank feeds a couple of small house loads along with windlass
and 3 HP bow thruster. All fwd circuits are protected by breakers or ANL fuses.
The aft high amp fuse block feeds SSB
, Inverter/ Charger
, Alt, IP Panel, Eng Starter, Fwd Bank. Some small fused loads are also tapped from the bus bar.
This set up has worked well for us for 10 years and I sleep pretty well knowing that I have covered most reasonable scenarios. Blue Sea Systems has some information about applying ANL fuses that you might find useful. They have a lot of delay in the trip curves.
Blue Sea also makes a Fuse (type BT if I remember) that connects directly to the battery screw terminals. I have always preferred to connect to the lead post so I passed on including them.
Tried to attach a pic of the high amp fuse block. Not sure if it will work