Switch panel and bus bar questions, need a bit of help!

[gandrew55]

Switches and fuse blocks--trying to sort something out.
So last year I got serious and added some electrical things to my 16'Duracraft flatboat. Dedicated trolling motor plug, navigation lights front and back, fish finder power and a plugin outlet. I looked hard at installing a switch panel assembly at that time but finally concluded that, by using some proper terminal extenders Johnny Ray Brass Terminals for both + and - , I could blade fuse each thing inline coming off the positive side and basically make everything 'plug and play.' This has worked great and was pretty simple to install.
Now I'm adding a bilge pump to the boat and it seems like maybe it's finally time to put in that switch panel.
Here's the question: do I need, in addition to the switch panel, bus bar terminals for both positive and negative runs? I want to keep things clean right at the battery, two big wires (plus separate breaker/wire for TM) but I'm unclear about which pieces I need to buy. I've attached links to photos of a bus terminal I was considering and the simple Johnny Ray terminals.
Any thoughts, ideas, suggestions appreciated!
https://www.amazon.com/Johnny-Ray-J...40&sr=1-1&keywords=johnny+ray+brass+terminals
https://www.amazon.com/Sea-426710-1...3_4?ie=UTF8&psc=1&refRID=3CD34FJ028H1HEJ4NEJ2

 

[Al U Minium]

Don't use any buss bars. If you want to keep everything at the battery, buy crimp style ring lugs to fit battery stud and stack 'em. Use one lock washer only for each battery stud. If you decide to install a remote panel things will get complicated fast. Have a good stout knife or small ax to cut the wires off the battery terminals fast in case of fire.

 

[timsmcm]

I am from the opposite camp. I say only 2 wires to the battery. 1 positive wire to switch, 1 negative to buss bar. No mess at the battery means no fires if the right gauge wire with the right fuses are used in the system. All of that with lots of care with every connection means trouble free electrical for many years.

 

[Ebug]

I'm with timsmcm....as well as 99.9% of all boat manufactures. Single wire from battery to fused circuit. A large capacity fuse should be placed within 12 inches on the positive side coming from the battery that covers the amp rating for the wire size and distance of that main power circuit.

Rob

 

[timsmcm]

I'm with timsmcm....as well as 99.9% of all boat manufactures. Single wire from battery to fused circuit. A large capacity fuse should be placed within 12 inches on the positive side coming from the battery that covers the amp rating for the wire size and distance of that main power circuit.

Rob

That is the only safe way to do it. Have your main buss close to your battery or batteries.

 

[gandrew55]

My current setup, without a switch panel but with each circuit fused inline coming off a Johnny Ray battery terminal, has one additional positive 8AWG wire coming off the battery with a 50 amp breaker for the trolling motor. (I only have one battery on this boat right now.) My question is really about trying to understand the switch panel + negative terminal setup, if I decide to go to the trouble of setting this up as I add the bilge pump. It's confusing when I look and see switch panels, fuse blocks and terminals all being offered for sale. If I buy a switch panel that comes with individual blade fuses, so I just need to buy a negative bus bar with it, or will I really need a fuse block? Is the fuse block really superior, if I can adjust the blades to match my application? (Looks like the breaker switch assemblies will limit control over what goes where.)

 

[DaleH]

My question is really about trying to understand the switch panel + negative terminal setup, if I decide to go to the trouble of setting this up as I add the bilge pump. It's confusing when I look and see switch panels, fuse blocks and terminals all being offered for sale.

Let's leave the bilge pump aside for the moment ...

Power Where Needed: I advise that you first figure out what YOU need to power, then let's discuss how to get the DC power up to the helm or your operator position. Recognize that some devices, like fishfinders, GPSs and such, already have an On/Off button, so you do not need to power them through a 'switch panel' with surface mounted toggle or those new plastic 'Contura' rocker switch, as it the rage nowadays. Those things typically switched through a switch panel (see picture) would be red/green navigation lights,deck/cockpit/courtesy lights, or even livewell pumps or aerators.

-Switch Panels usually don't have any ground buss on them for the items, but may have a -lead for grounding of any LED lamp used to indicate 'lit when powered', if equipped.

-Fuse/Breaker Panels can be purchased with just a +positive side, but the better ones (as pictured) have a built-in negative buss on them, which make the wiring runs cleaner and more understandable. Man, I look under some helms, even of 'new' boats ... and I just shudder :shock: !

I'd put a fuse or breaker-equipped panel (also see picture) up where needed (I enclose them in a tupperware box with snap-on cover, to protect them from the elements), by a main run of #8 or suitable AWG +/- wires, properly sized to handle the total ampacity of all of the loads that you would run at the same time, worst case. Those items with built-in switches would be powered by this fuse/breaker panel.

If you still had 1 or 2 needs to have those items switched ... then just get a dash-mounted switch panel with the number of circuits needed, plus 1 or 2 to have room for future expansion. This switch panel would be powered by 1 heavy lead off the fuse/breaker panel, where the wire would have ample rating to power ALL of the devices run off the switch panel.

Bilge Pump: Personally I like the dedicated 3-way switches of On - Off - Auto. The 'On' +wire would be powered by the fuse/breaker panel, with the 'Auto' +wire run back to the battery positive post to power the pump automatically (even if you had a battery switch and it was switched of Off). The ground would go to the negative side of the fuse/breaker power panel.

Buss Bar: To me, I've never had to use one in a small boat, say < 18' or so. A better alternative than a pure buss bar, is a power post. On larger boats where I'm running two batteries (thru a battery switch of "Off - 1 - Both -2") I will use a $20 'Power Post' by Blue Seas for all of the negative ground connections in the stern. This would be mounted in a home made DIY tupperware-type plastic box to try to keep it as corrosion free as possible. See picture.

The negatives of both batteries, as well as the OB negative cable, are connected here. The beauty of the system is that even whilst off-shore or in an otherwise dangerous/emergency situation ... I can pull one of the batteries out of the circuit and off the boat without disturbing my ground loop. I see too many tie the grounds together on their boats, where only one ties to the buss bar. That's a 'no good' limiting situation to me.

Whew ... does any of this help? Break it down into pieces ... and it might help you process all of this ...

 

[gandrew55]

DaleH,
Thank you! Very helpful. I like your logical explanation. Hoping to work on this this weekend.

 

[gandrew55]

DaleH,
One question: how does that boot on the power post work?

 

[DaleH]

One question: how does that boot on the power post work?

Cable goes through the boot, then the cable ring connector is attached to the post. Serves to somewhat protect it against elements and stops items from contacting it that could bridge a connection, say a wrench used to remove a nut off the positive post of a nearby battery. If the wrench hit a +pos to a -neg post anytime, there'd be a big spark like in welding, as ALL the amps in the battery dumped through the wrench.

I still don't see the need for such a post on smaller boats, the most I ever used on one were for the battery & OB cable leads, then smaller ground wiring like stern light, 2 stern bilge pumps, livewell/washdown pump, and stern 12VDC aux power socket.