Distributed Electrical Systems or Standard Panel? Which do you like?

[Chotu]

No end to topics here. I hope it’s a fun one. This is an interesting issue I’m not yet passionate about, but I’m sure some of you are.

I’m currently (no pun intended) debating between a distributed DC electrical system and a traditional one.

Distributed system : Large wires are run from the battery area to a large load, such as the windlass or electric winch motors. You then tap into this large cable to position small breaker panels where they are needed, supposedly resulting in less weight and shorter, easier wire runs to the end components.

Traditional system: A huge distribution panel is near the batteries and wires are run from all the breakers on the panel to all the individual components one at a time.

Which do you like? Why do you like it?

I’m probably leaning toward distributed.

[rslifkin]

I've got somewhat of a mix of both. There's the factory provided main panel (which is right next to the AC panel) that covers the majority of DC circuits. The high amp DC distribution is on the forward engine room bulkhead, just opposite of the house batteries. That's where the house bank switch and main house bus bar live. All high amp breakers are mounted to that bulkhead (things like windlass, inverter, main panel feed, etc.) That keeps the high amp runs more direct, but gives a central control point for all of the other stuff.

[Dsanduril]

I think a catamaran somewhat naturally lends itself to a distributed system with a panel in each hull (or even one fore and one aft in each hull) and one more in the main cabin. At least on our boat it’s about a 20m/70ft run from the starboard bow head/sail locker back to the main panel on the port side of the cabin.

Does depend on what equipment you have and where. If all you have at the remote locations is a bunch of LEDs then running big wires and separate panels isn’t really needed, but if you have some bigger loads out there distributed can be cleaner and more efficient.YMMV

[rslifkin]

Originally Posted by Dsanduril

I think a catamaran somewhat naturally lends itself to a distributed system with a panel in each hull (or even one fore and one aft in each hull) and one more in the main cabin. At least on our boat it’s about a 20m/70ft run from the starboard bow head/sail locker back to the main panel on the port side of the cabin.

Does depend on what equipment you have and where. If all you have at the remote locations is a bunch of LEDs then running big wires and separate panels isn’t really needed, but if you have some bigger loads out there distributed can be cleaner and more efficient.YMMV

That's a good point. On a cat, I'd probably do main high amp distribution right near the batteries and have breakers and then runs for the following: port hull main, stbd hull main, bridge deck main, windlass, and any other major high amp draws. Each of those 3 mains would go to a panel that would handle distribution in that area.

[Frankly]

I have a distributed electrical system. Main ANL high amp fuse block adjacent to battery bank/ switches. 5 panels located around the yacht with smaller breakers feeding nearby loads. This concept was based on standard practice for commercial building distribution systems. After 15 years has worked well in daily use and future expansions.


Frankly

[Tupaia]

I have two house banks with two panels one in each hull, no start batteries. Having a single battery bank is more efficient for charging but the weight saving of wiring crossing and the bridgedeck and weight saving by not needing start batteries outweighed (pun) either a traditional or distributed system. There is a pair of wires and a Pathmaker connecting the two battery banks giving charging and redundancy.

[kirklkjb]

Originally Posted by Tupaia

I have two house banks with two panels one in each hull, no start batteries. Having a single battery bank is more efficient for charging but the weight saving of wiring crossing and the bridgedeck and weight saving by not needing start batteries outweighed (pun) either a traditional or distributed system. There is a pair of wires and a Pathmaker connecting the two battery banks giving charging and redundancy.

I like the idea of providing redundancy via a switch and removing starter batteries. A mention I've heard is a set of jumper cables but that does not seem feasible on a large cat.

So what type of switch are you using. I'm assuming you'd be using one that is break before make and is either Ain to Aout and Bin to Bout or Ain to Bout or Bin to Aout or OFF etc.? Do you have a switch position that shorts Ain and Bin? I.e. Ain+Bin to Aout+Bout? Seems risky to me as the voltages better be identical to short Ain+Bin together?

[Chotu]

Is this the right forum? Never have I seen everyone agree on the same thing. Ha ha. Good to know. This is the way I was leaning anyway, so I might as well go through with it especially given the blessing of everyone. I currently have a rudimentary temporary electrical system in here. It is basically some fuses, a few odds and ends, and a bunch of extension cords. The boat is of course, under construction at the moment. However, you can navigate it, and it has a refrigeration and stuff. Running lights. But that was all quick and dirty to get it in the water. Soon on the list will be redoing the electrical system properly.

[michaelratinter]

Mine is same as rslifkin above. Breaker panel for lamps, pumps, comm, etc. and inverter and windlass on forward bulkhead of engine room.

[Chotu]

Originally Posted by Tupaia

I have two house banks with two panels one in each hull, no start batteries. Having a single battery bank is more efficient for charging but the weight saving of wiring crossing and the bridgedeck and weight saving by not needing start batteries outweighed (pun) either a traditional or distributed system. There is a pair of wires and a Pathmaker connecting the two battery banks giving charging and redundancy.

This is pretty interesting. I have one starting battery for each motor currently. They are not connected at all to the rest of the electrical system. Not even a little. As a matter fact, my outboards, being newer ones, need a special kit in order to even get Current out of them to charge batteries other than a starting battery. Stupid design. So I never bothered. With all of the solar and generator.

You have me wondering what they would do if connected to a house bank. If they were treated as a starting bank and allow Current to charge the house bank or not.

[roland stockham]

I like distributed panels. Cabin Lts & services, pumps and machinary, nav & chart table etc. Mainly because it makes wiring simpler. Large bundles of wires behind a single panel can be difficult to work on. There is also the point that if you get a fault that damages the wiring everything has to go off not just one panel.

[rslifkin]

On the battery thing, if cruising in areas where the engine(s) are important, I consider starting power to be safety critical. 1 start battery per engine is my preference. Generators can share with main engines though. House batteries should be separate so that electrical problems or human error is very unlikely to impact the ability to get the engines running.

On my setup, I've got 3 banks, which we'll call S1, S2 and House. Each engine and the generator have a 1/2/both/off switch and can use either S1 or S2 to start. Normally, port engine uses S1, stbd and generator use S2. House is independent. There's a 3 bank charger that charges S1 and S2 and could charge House in an emergency (the wiring exists, but breaker is left open).

Normally the inverter/charger will charge House (as well as the upcoming solar install). Underway, each engine has an ACR that parallels it to the House bank to allow the alternators to charge the House. However, my ACRs are ignition interlocked, so once the engines are off, they won't activate and the start banks remain 100% isolated (and only receive power from the shore charger).

[zstine]

whatever way you locate your circuit breaker boxes, I would use the DIN mounted relay style breakers (with manual override) as apposed to the old style panels where you are manually switching the breaker on the panel. This means the breakers can be hidden and they can be actuated by low current switches, including smart switches... so you can operate the boat's electrical system via web-based / bluetooth apps.

[walbee]

This article on marine digital switching may be of interest.

https://www.seamagazine.com/digital-switching-on-boats/

[Chotu]

Wait a second! The traditionalists are just being quiet! The poll is unanimous for traditional panel and wire runs. The verbal side here is all pro distributed system.

Very interesting