Musings On Boat Electrical Panels

[jviss]

I find boat electrical panels frustrating. It's technology and practice that's at least 50 years old, maybe even older, going back to the 1930's! I have the typical thing, an array of circuit breakers that are screwed from behind into a cutout aluminum panel. Each vertical row of breakers is connected together by a positive flat bar, and there's an adjacent negative bar with threaded holes to secure the negative wires for circuits. There are a couple of analog meters, a switch to select which bank the Voltmeter reads, and a DC Ammeter for the panel current.

The AC panel is similar.

There are numerous problems with this. One of the most annoying is that to change a faulty breaker one must unscrew the entire vertical row of breakers from the panel, and then unscrew the faulty breaker from the plus bus bar and circuit wire. To do this safely requires de-energizing the whole panel, and man, that's a lot of screws!

Meanwhile, our ancient AC panels at home use plug-in breakers, and the panel has just cut-outs to expose the working part of the breaker. How is it that this technology hasn't migrated to boat panels?

My meters are all faulty and inaccurate, the breaker/switch legends are not illuminated, and so on. I'm so tempted to make a completely new panel, as I did for the Catalina years ago. But even then, there are no pluggable DC breakers that I'm aware of! Does anyone know of any, and a compact cabinet that they would plug in to? I don't think so.

Just complaining, I guess, but interested in folks' views, and whether they care about this, too.

 

[dlochner]

One of the most annoying is that to change a faulty breaker one must unscrew the entire vertical row of breakers from the panel, and then unscrew the faulty breaker from the plus bus bar and circuit wire. To do this safely requires de-energizing the whole panel, and man, that's a lot of screws!

Not on my panel. remove the lead, unscrew from the bus bar, and remove 2 small screws to release the breaker.

 

[jviss]

Not on my panel. remove the lead, unscrew from the bus bar, and remove 2 small screws to release the breaker.

Nice! Yea, my bus bar is on top of the breakers, maybe it should have been installed on the bottom!

 

[mermike]

Vibration is a significant problem with home-style plug in circuit breakers. They certainly are a source of trouble in RV electical systems.

Blue Sea's 360 modular panel system is very nice. I used a 1x3 frame and setup for my AC panel.

 

[Davidasailor26]

Beneteau goes a different route. The panel switches are just switches on a PCB. The back of the panel houses blade fuses for the individual circuits. Large loads (like the autopilot motor) are switched indirectly by the panel - the panel switch/fuse triggers a relay with a separate higher amperage fuse to the device. Negatives are tied together at a Wago terminal block behind the panel. The whole panel hinges down for easy access. The panel also has a digital volt/amp/tank monitor that’s acceptably accurate.

Not saying this is hands-down better than the traditional way. For one thing it has lots of reliance on non-resettable fuses. But the ease of access and general functionality is pretty nice.

 

[jviss]

Beneteau goes a different route. The panel switches are just switches on a PCB. The back of the panel houses blade fuses for the individual circuits. Large loads (like the autopilot motor) are switched indirectly by the panel - the panel switch/fuse triggers a relay with a separate higher amperage fuse to the device. Negatives are tied together at a Wago terminal block behind the panel. The whole panel hinges down for easy access. The panel also has a digital volt/amp/tank monitor that’s acceptably accurate.

Not saying this is hands-down better than the traditional way. For one thing it has lots of reliance on non-resettable fuses. But the ease of access and general functionality is pretty nice.

That's interesting. Clever design.

 

[Tally Ho]

On my old O’Day 322, I was able to add a single breaker (DC side) with out removing all of the other ones.

The technology seems old school, but then again my boat is 35 years old…

Greg

 

[Stu Jackson]

Each vertical row of breakers is connected together by a positive flat bar, and there's an adjacent negative bar with threaded holes to secure the negative wires for circuits.

Are you sure? Aren't the negatives "common" and the individual wires for the + side?

 

[jviss]

Are you sure? Aren't the negatives "common" and the individual wires for the + side?

One side of the row of breakers is the positive feed, via the bus bar, the other side of the breakers are where the individual wires/circuits connect. Then there's a neg bus bar as well.

I'm going to take another look when I get there today. Maybe I'm mistaken about removing the breakers, but I'm pretty certain I have it right.

 

[jviss]

Follow up: yes, confirmed. On mine, because of the way the plus bus is attached to the breakers, one would have to pull all the breakers from the panel to get one out, or remove the plus bus from all the breakers. Take your pick.

 

[Tally Ho]

So, if you unscrew the bus screw, and the + wire, the breaker doesn’t snap out ( to the left in this photo)?

It just seems crazy that you would have to remove them all to upgrade or replace one…

Do you have any open slots?

Greg

 

[dlochner]

No, just remove the mounting screws on the front of the panel and the breaker should tip out the back.

 

[jviss]

No, just remove the mounting screws on the front of the panel and the breaker should tip out the back.

I can try that. I don't have a failed breaker at the moment, but I may be changing a couple due to current ratings, and reconfiguring things.

 

[Davidasailor26]

I can try that. I don't have a failed breaker at the moment, but I may be changing a couple due to current ratings, and reconfiguring things.

I did just see something like this on one of the YouTube channels I follow. It wasn't exactly clear to me what he had to loosen because I don't have a panel like that, but in case it's at all insightful, it starts at 4:30 on

.

 

[BAD ORCA]

Follow up: yes, confirmed. On mine, because of the way the plus bus is attached to the breakers, one would have to pull all the breakers from the panel to get one out, or remove the plus bus from all the breakers. Take your pick.

On my original panel they soldered a copper rod across the back of all the breakers. I cant tell if they also drilled holes and soldered the rod through the holes or not. I never bothered to try and remove any and just built a new panel.