Quote:
Originally Posted by PorFin
Chip,
Forgive me if I'm missing something here, but it seems to me that 150 amps is overkill. Have you totaled up the number of amps all of the connected devices actually use? The SSB seems to be your biggest load, and that's probably going to be around 30 amps (check your documentation.) The VHF is likely less than 10 amps, and the others are probably also in the low single digits.

OK that seems like what I am looking for. This is what I need to understand.
It would be 17 + 15 so 32 feet round trip.
32’
Do I size the wire to the total fuse block or to the size of the loads?
It seems to the size of the loads.
There are 12 – 30 amp fuse slots. I do not know of any that will be 30 amps. Like you said maybe the SSB which we do not have yet.
So if we have say a bilge alarm (I forget the amps) but say 10.
Then say the propane detector say 10.
Then say the VHF at say 10.
Then thermostat for the new refer we are getting say 10.
OK then just to make it easy for me say 10 on all of the 12 fuses.
Then I would say ok that is a 120 amps, darn that seems a lot too.
Ok say 10 on 6 fuses and 5 on 6 fuses.
That is 60 plus 30 amps on the fuses.
So 90 amps. None is critical so say 10 percent drop on 90 amps?
This seem right?
So I could go with 3 AWG for 32’ and get a 9.73 percent voltage drop.
I can probably drop these numbers down further.
Another question:
In the chain and anchor locker we have 3 LED lights all fused together to a 5 amp fuse.
That seems ok. It was a suggested way to go rather than fuse them separately.
Can I then following that example put two or three items to one fuse if the all together add up to the 5 amps? Would that not over fuse one of the three items?
Also what size fuse would I use to fuse the 90 amp fuse block? Just a guess but 80 amps?
Thanks,
Chip