Where to put the fuse

[Dave K]

Is this fuse location ok or should I have a fuse on the other side of switch?

[chpthril]

what are the red and black colored rectangles?

[Dave K]

what are the red and black colored rectangles?

Those are distribution blocks, and main wire from batteries is an 8ga

[chpthril]

Ok, no need for fuse on other side of switch since you cant run fill and drain pump at same time.

[Dave K]

thanks for the help Mike

[Dave K]

The run from the battery is approx 13.5 feet in the diagram.

Could I use 10 gauge to the distribution block rather than 8ga. The total possible draw is 4 pumps going at once which would be 16 amps potentially 20 amps?

[jason@wakemakers.com]

As drawn both fuses are necessary. You need to have a fuse within 12" of the battery so that you don't have an issue if the jacket of your 8AWG supply is pierced. You also need individual fuses for each circuit because 25A will fry your switches.

The better way to do it (in my opinion) would be run individual feeds for each switch, that will reduce your cost in wire, reduce the number of components, and give you better protection.

[chpthril]

^^^ As drawn, there is 25A circuit protection for the trunk line supplying B+ to the distribution blocks, which will supply power for other devices i believe. After the block, there is a 5A fuse protection for each switch.

No need for fuse on the fill pump after the switch or on the drain pump after the switch. Since the rocker switch CAN NOT allow for both the fill and drain pump to run at the same time, the 5A fuse on the B+ side on the switch will serve as the switch/pump circuit protection whether the full or drain pump is in use.

IMO, KISS and go with the trunk line V's using 9 fuses and a ton of wire runs and lots of connectors. I see no reason why you couldn't get your B+ off the helm BUSS. Most are fed by 4ga cabling. This would save you from running all the way back to the battery. 12ga would be all that is needed here.

[jason@wakemakers.com]

Maybe I'm looking at a different drawing, but Dave doesn't have any fuses after the switches in the one posted in this thread.

As it's drawn above, both fuses are needed. I agree with Mike though, since you're only using aerator pumps the better option would be to pull power from the buss bar under the dash with an individual fused lead for each switch.

[chpthril]

Maybe I'm looking at a different drawing, but Dave doesn't have any fuses after the switches in the one posted in this thread.

As it's drawn above, both fuses are needed. I agree with Mike though, since you're only using aerator pumps the better option would be to pull power from the buss bar under the dash with an individual fused lead for each switch.

We are looking at the same schematic. There are no fuses after the switches in his schematic, and they are needed. With an ON/OFF/ON toggle switch, you can run a fill and drain pump off one switch, but not at the same time. Due to this, the only load going through each switch would be one pump, (maybe 2 if he runs 2 drains on the bow sac), so the single 5A fuse would do it.

There will not be any voltage on the pump (switched) side of the switch, until the switch is activated. At this point, IF there was a short, the 5A fuse would blow. This is true regardless of where the fuse(s) is located.

Jason, if i am reading your recommendation correctly, David would need 9-10 fuses to wire the circuit: 1 on the trunk B+, 1 for the B+ side of each switch (where are 4 now), and one after the switch in each switched B+ going to each pump. Thats 2 for each switch for a total of 6, so now we are at 10. This would be 9 fuse holders under the helm behind the switches! Thats a whole lot of extra connections (potential points of failure) that do not need to be in the circuit.

Dave, your schematic is solid, roll with it

[Dave K]

I picked up a 8 gang fuse block each that will had a separate 5 amp fuse, so:

Battery - 25 amp fuse - 13.5' run of 8 gauge-distribution block - 14ga to 8blade fuse box (5 amp fuse) - switch - pump

I'll daisy chain power to one side with 14 ga.

http://www.quickcable.com/products.php?pageId=642

[Dave K]

Dave, your schematic is solid, roll with it

The only difference is the fuse block on battery side of ballast switches. Seems that will keep things nice and clean.

[Dave K]

I think this is alittle more clear.