Wiring upgrade case study

[DanielI]

I’m in the midst of installing new solar and instruments on my Catalina, and I’m finding a bunch of things I’m concerned about. Rather than posting a bunch of threads, I though it might me helpful to others if I documented my progress if some knowledgeable folks are willing to weigh in. I have read through Nigel Calder, and I’m generally knowledgeable about electrical circuits, but I have no experience with marine systems.

Let me start with a general picture of my panel and batteries. As you can see, the wiring is not terribly rats-nesty, but it could be better. Some concerns I have (as in, things I’m assuming need fixing) to begin with are:

1. There are no fuses on wires coming off the batteries, just on the panel.
2. It seems the DC negative is grounded to the AC ground. At least, I see continuity between my DC negatives and the black wires on the bottom of the panel, which are part of the AC. There is a big bus with green and white wires you can see behind the panel, but I can’t figure out where it connects.
3. The AC also not physically isolated, i.e., I can get to the wires without a screwdriver. FWIW, the AC is not a priority, as I do not currently use it (no inverter, no access to shore power).

A final comment: I’ve seen some similar threads in the past responded to with either, “get a book,” or “you can’t learn this stuff on a forum.” I’m happy with additional book suggestions (I’d appreciate comments on Boatowners Electrical Handbook by Wing or Replacing Your Boats Electrical System by Westin), but you can’t learn everything from books. Some things you learn by the questions that come up when doing, so I hope some of the experts here are willing to help out, and that maybe this will be useful to others, too.

Thanks in advance.

[Jammer]

Originally Posted by DanielI

. Some concerns I have (as in, things I’m assuming need fixing)

It depends on your goals for the boat and the amount of time/money you believe it is wise to devote to electrical matters. Often other needs i.e. sails, standing rigging, safety equipment, auxiliary propulsion, are more pressing.


It is odd to have battery box lids with no battery box to support them


You can add MRBF fuseholders to the + posts of the batteries without having to change anything


You can use tape, heatshrink, or nonconductive caulk (silicone) to cover 120v terminals that you believe pose a hazard


If you are out of breaker and bus space you can add another bus and another small breaker panel alongside what you have without having to rip out existing wiring


Wholesale replacement of working factory wiring is costly and time consuming and rarely results in a safer or more functional boat

[dfelsent]

The lids are likely there to act as a cover for the otherwise exposed positive terminals. Looks like the batteries are in a box, just not individual boxes.
And yes I’d put covers over the exposed AC and look at MRBF fuses for the batteries.
Go for safety then figure out your other priorities.
And go sailing!

[Spot]

A picture of the front of the panel would be neat to see.
Are the batteries (1) for 'start' and (1) for 'house' connected to the selector switch?
Is there a schematic from Catalina that starts to explain the system?

It does look over-switched and under-fused but hard to say 100% unless we know if the panel components are switches or breakers. I have seen much worse...

[Stu Jackson]

Here's the longer answers: They all come from my
Electrical Systems 101 Electrical Systems 101

***************************
OEM 1-2-B Switch Wiring History Alternator/Batteries & "The Basic" 1-2-B Switch BEST Wiring Diagrams

1-2-B Considerations (New 2020 - Rod finally got around to diagramming what I had done in the above link in 2009 )
1/2/BOTH Switch Considerations

Basic Battery Wiring Diagrams This is a very good basic primer for boat system wiring: Basic Battery Wiring Diagrams

This is another very good basic primer for boat system wiring: The 1-2-B Switch by Maine Sail (brings together a lot of what this subject is all about)
1/BOTH/2/OFF Switches Thoughts & Musings

This is a newer primer for boat system wiring design with a thorough diagram: Building a Good Foundation (October 2016)
Building a DC Electrical Foundation

What are ACRs, Combiners & Echo Chargers? (by Maine Sail) [scroll to the top]
Battery Switch Question ? and Battery isolator / voltage regulator / batteries

Making Sense of Automatic Charging Relays (2019)
Making Sense of Automatic Charging Relays - Marine How To

[DanielI]

Thanks, all. This is exactly the kind of discussion I’m looking for.

This morning’s discovery is the crimp connector coming off the middle switch, one from the left. It’s not visible in the picture, but there are two wires coming out of the crimp on the other side, one going to the instruments, and one going to the VHF radio. As I’m replacing my instruments, I was going to attach the NMEA power cable here. I was going to put a blade connector on my NMEA cable and connect directly to the switch, but that cuts out the radio. Butt connector on the old instrument (+)? Or is the 1-2 butt connector calling out for replacement?

Some general comments:
1. Winds are quiet this morning. I was sailing yesterday, and will pack up the tools again when it picks up enough.
2. As far as I can tell, the batteries are in a built in fiberglass compartment, with no openings except where the wires enter. But the compartment itself has no lid, other than the MDF lid we have for all our settee access panels. I assume that’s why the plastic battery lids, which strap to the compartment.
3. My general goal is not to rip out and replace extensive portions, but I would like to upgrade or replace anything that is below spec or a presents a hazard. Part of what I’m looking for in this thread is advice on what is in need of replacement, and what is better left alone. I agree, it doesn’t look nearly as bad as some.
4. I’m attaching a picture of the panel front. It is a standard 1-2 switch, currently. I’m thinking of re-wiring that part to have a dedicated start battery, eventually (discussion on a separate thread).

[Stu Jackson]

Originally Posted by DanielI

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2. As far as I can tell, the batteries are in a built in fiberglass compartment, with no openings except where the wires enter. But the compartment itself has no lid, other than the MDF lid we have for all our settee access panels. I assume that’s why the plastic battery lids, which strap to the compartment................
.....................................

Almost all Catalinas regardless of size were built with battery COMPARTMENTS that way. I've had three Catalinas and been on hundreds more.



They are NOT battery boxes.


You NEED battery boxes.


Why? 'Cuz the acid in a battery will eat right through the fiberglass compartment.


Please, be safe.

[JoeRobertJr]

Originally Posted by Stu Jackson

Almost all Catalinas regardless of size were built with battery COMPARTMENTS that way. I've had three Catalinas and been on hundreds more.

They are NOT battery boxes.

You NEED battery boxes.

Why? 'Cuz the acid in a battery will eat right through the fiberglass compartment.

Please, be safe.

Thanks for the safety tip. My Catalina 25 has two batteries in that compartment that are too tall to add battery boxes. I wonder if there is an acid-resistant coating I can apply to the inside of the compartment.

Otherwise, I would have to relocate the batteries. I had considered moving them to the port locker, which would also solve my starboard list problem.

[DanielI]

Originally Posted by JoeRobertJr

Thanks for the safety tip. My Catalina 25 has two batteries in that compartment that are too tall to add battery boxes. I wonder if there is an acid-resistant coating I can apply to the inside of the compartment.

Seconding that thank you. I assumed they were compliant boxes based on the layout, which clearly was naive. I see that Catalina Direct sells a battery box they claim is sized for the compartment on both a Catalina 25 and 30 (what I have). I’ll let you know if it really fits.

[Spot]

Battery acid is strong stuff. I recently 'let' a loose marine battery tip over in my car (it was unboxed and unstrapped) and the carpet in the cargo area was reduced to an oily goo which proceeded to ooze down into the wheel well for the spare. A couple hours with water and baking soda and it's still a mess. I should be more thankful nothing more happened like a dead short or a vehicle accident where the battery could have become a projectile.

Back to DanielI's boat: Stu, would you say that panel is typical for a Catalina? It looks like there are several breakers (with the chrome panel nuts) feeding columns of panel switches. What function is the 1-2-Both-OFF performing in this boat?

[sinnerman]

I also have a Catalina 30 . The guy I purchased the boat from had gutted the electrical system as the previous owner had turned the poor vessel into a science project. It had more antennas and wiring than air force one..

So it had an electrical panel, two batteries, one working light over the chart table and some AC wiring. The rest I had to figure out and reinstall.

The first thing I did was trace down any remaining wires and label them. I purchased an EPSON LW-PX300 printer which prints on heat shrink tubing so I could label the wires. The heat shrink label cartridges are not cheap, but it is well worth it. I label ALL of the wires in multiple locations so I can identify them in the future.

For the larger wires (AC cables) , I printed adhesive labels and secured them with clear packing tape.

I took a Marine Electrical Systems course from the US Power Squadron (now called "Americas Boating Club). Even though I am already an engineer, I learned a lot. You may be able to take the course online. My was tutored via the internet. https://americasboatingclub.org/cour...trical-systems

You need a ratcheting crimper, a good automatic wire stripper and a heat gun for the labels, heat shrink tubing (with adhesive) and heat shrink electrical connectors. I use ANCHOR connectors. Also MARINE GRADE wire / AC cable only. You can get some good pricing from www.Genuinedealz.com


" 1. There are no fuses on wires coming off the batteries, just on the panel".
I have no battery fuses either. It is on the "to-do" list. I am sure that most boats do not have them installed as well. I also plan to add one fuse each to the two fuse blocks that I installed (50A each..?) to keep them from melting in the event of a short.

"...2. It seems the DC negative is grounded to the AC ground."
This is correct per ABYC. Technically, connect the AC green ground to the engine block. ( Green AC ground, NOT AC neutrals!!.)

I have not done this yet on my boat. I saw some blog comments stating that this was not a good idea due to possible electrical erosion underwater, and need to look further into it.

I did however install a galvanic isolator in the AC ground (Green) wire going to the shore power connector.


3. "..The AC also not physically isolated, i.e., I can get to the wires without a screwdriver..."
I installed a Blue Sea plastic cover over my AC breakers. Big shock hazard... https://www.bluesea.com/products/402...-1_4_x_7-1_2x3


Cheers

[OBT]

Your electrical issues seem minor to me Just about to straighten out the previous owner's legacy wiring.

A really good series to watch is
https://www.youtube.com/user/PacificYachtSystems - very informative.

[Captain Anthony]

Following

[Stu Jackson]

Originally Posted by Spot

Battery acid is strong stuff. I recently 'let' a loose marine battery tip over in my car (it was unboxed and unstrapped) and the carpet in the cargo area was reduced to an oily goo which proceeded to ooze down into the wheel well for the spare. A couple hours with water and baking soda and it's still a mess. I should be more thankful nothing more happened like a dead short or a vehicle accident where the battery could have become a projectile.

Back to DanielI's boat: Stu, would you say that panel is typical for a Catalina? It looks like there are several breakers (with the chrome panel nuts) feeding columns of panel switches. What function is the 1-2-Both-OFF performing in this boat?

Great story about battery acid. I think I'll save it for when the next joker asks.


No, it is NOT an OEM Catalina panel, it was replaced with this one.


Without a wiring diagram, no one can answer what the 1-2-B switch is doing.


Photos of wiring without a wiring diagram are useless.

[westwon]

Hi Stu.


Just a note that most of your hot links aren't working.


Steve