Association Forum - Electrical questions

Assn Members Area · Join

Home.

Association Forum

Ships Store

Cruising

Racing

Technical Tips

Photo Gallery - New

Boat Search - Updated

Manuals & Brochures

Swap Meet

Links

Officer Flag Line & Staff

Bylaws & Constitution

Members Area

Join the Association

Notice:
The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.

Association Forum

Username:	Password:
Save Password
Forgot your Password?

All Forums

Catalina/Capri 25/250 Sailor's Forums

General Sailing Forum

Electrical questions

New Topic

Topic Locked

Printer Friendly

Author

Topic

glivs
Admiral

Member Avatar

USA
836 Posts

Initially Posted - 04/06/2011 : 05:04:23

The big project this spring will be electrical reorganization/upgrades. Still in planning mode but to start...

- Do you route the negative line from the engine(starter/alternator) back to a battery or to a negative bus bar?

- Does anyone place a switch (e.g. key switch) in the positive line to the engine?

- There are many warnings about the need to prevent hydrogen gas build up in the battery compartment, yet neither Catalina nor most boat owners that I am aware of have taken any steps to do so. Our battery compartments (beneath quarter berth in our case) are pretty much isolated from any free exchange with outside air. Is it worth adding a small vent in the compartment wall into the cabin or is this really a non-issue? Underlying this question is that the back of our distribution panel is in the same enclosed area as the battery compartment.

As always, thanks for your input.

Gerry Livingston, Malletts Bay, VT
"Great Escape" 1989 C-25 SR/WK #5972

Edited by - on

OLarryR
Master Marine Consultant

Members Avatar

USA
3467 Posts

Response Posted - 04/06/2011 : 14:10:54

The negative can go to the battery or to a negative bus bar. I have 2 batteries. My outboard negative goes to one of the negative battery posts. My positve cable from the outboard goes to my battery switch and i can then start the outboard with battery 1, battery 2 or both. I tend to very rarely ever touch the battery switch. i leave it in the "Both" position.

My thought regarding hydrogen gas is that the battery compartment, at least on my boat, is not really a closed off sealed compartment. The area is open to the whole quarterberth area and believe also under the cabin bunks. Catalina may not separately provide a vent because the area is fairly large proportionately compared to the amount of hydrogen that is given off from the batteries....but that is just my guess and would have to dig deeper to see if it can be substantiated by a techncal reference.

If your boat is set up like mine, then your switch panel is under the steps and quite inconvenient for turning on the nav lights, etc as it gets dark. This is an issue for me when others have to turn the switches on or if I go sailing by myself, I have to leave the cockpit unattended to find the right switch. So...if you are doing electrical upgrades, you may want to consider hooking up an addl switch panel that is accessible from the cockpit area. I located one in front of the sink. My website has addl photos of electrical upgrades - battery charger and fans.

Edited by - OLarryR on 04/06/2011 14:13:28

glivs
Admiral

Members Avatar

USA
836 Posts

Response Posted - 04/06/2011 : 17:12:49

Thanks Larry. We have very similar boats so I have visited your web page several times particularly as you are 2-3 projects ahead of me so I'm benefiting greatly

And yes, I do plan to add a new switch panel although not sure which one at this point. The original panel behind the stairs is anything but friendly. I've re-read most of the electrical discussions over the past year or so but may not get to my boat for another month (commitments/house projects/...). Just thinking out loud.

I agree the volume beneath the quarter-berth is quite large and I suspect that temperature differentials between hull and cabin could lead to significant convective mixing in that space so venting the compartment is probably not worth the trouble. I was just curious if anyone had thoughts.

Edited by - on

OLarryR
Master Marine Consultant

Members Avatar

USA
3467 Posts

Response Posted - 04/06/2011 : 20:07:01

Gerry,

One thing that you may want to consider as the main sailing season is coming upon us is to perhaps take care of some rather small projects right now. Basically some maintenance or must do things and save a major undertaking for the late Fall as the sailing season winds down. At least for me, I found that starting a major project as Spring kicks in just sets me up for a project that gets half done or a project that takes me away from sailing. This kind of happened with me when I was getting started on my table project. I got started but then put it on the backburner because I was then drawn into the conflict of working on the project or go sailing. Go sailing was what usually won out.

Edited by - on

Voyager
Master Marine Consultant

Members Avatar

USA
5379 Posts

Response Posted - 04/06/2011 : 20:45:35

I agree with Larry on that. Few years back I got so involved with repainting the bottom in the spring that I missed my launch date and was behind the eight ball for two additional weeks where I could have been sailing. While I was glad to have the job done right, I still felt "cheated" out of two weeks on the water.

On the routing of cables and switches for the battery, let me make one very important statement: if your engine has an electric start and an alternator, DO NOT include a switch between the engine and your main battery since you can easily burn out your voltage regulator and rectifier diodes with one thoughtless flip of a switch.

That mistake will cost about $80 for the part and another $100 to install it if you have to take it to the repair-person. You should, instead include a 60-80 amp fuse in line right next to the battery in case all hell breaks loose and a short develops. But a switch is not needed on the engine circuit.

That said, you should have a switch between the battery and the house (DC electrical panel) and this should be a second circuit. Also, if you have two batteries, you should always have a way to disconnect one from the another, and a way to disconnect them singly or collectively from the house circuits, but you should always keep one battery PERMANENTLY connected to the engine if you have an alternator.

A negative bus bar is a good idea, as it lets you connect all the negative leads (including the engine) together neatly and without crowding. It will give you a good, low resistance connection for all components. I bought one at the electrical supply house for a 240 volt, 200A service. I also put in a positive bus bar to lead to the electrical panel. I did not connect that to the engine's positive lead however, since the house fuse is only 30 amps, and does not provide enough power for my engine's starter.

Hydrogen is produced when the battery electrolyte boils from overcharging the battery, but under normal charge/discharge conditions, is not an issue unless the space is absolutely air tight.

If however you do smell hydrogen sulfide gas (rotten eggs) during operation, you have a regulator problem. The engine alternator's regulator, or the regulator on the plug-in battery charger is not limiting voltage during the charging cycle. This requires immediate attention, or else you will ruin your batteries, or worse, create an explosive atmosphere which could cause a tragedy.

If you're wondering why I know about this, well, I had switched off the alternator when the engine was running, I blew my regulator and I boiled my electrolyte.

Experience is the best teacher.

Edited by - on

Stinkpotter
Master Marine Consultant

Members Avatar

Djibouti
9081 Posts

Response Posted - 04/06/2011 : 21:47:58

Bruce! You turned the battery switch I installed "Off" while the engine was running?? OUCH!

BTW, I installed that switch so that if something went haywire (a short/fire/??), I could isolate the engine from everything and keep motoring. It also allowed me to make the engine a little more "dead" in the marina--less responsive to mischievous fingers. I had no problem remembering to turn it on--the starter was dead till I did. I only turned it off as part of the process of closing up the boat before leaving it.

Edited by - Stinkpotter on 04/06/2011 21:52:29

OLarryR
Master Marine Consultant

Members Avatar

USA
3467 Posts

Response Posted - 04/07/2011 : 03:14:15

I agree with Bruce that a battery switch between the outboard and the batteries can cause issues with ruining the voltage regulator. Buried in the archives is more comments on this subject. My boat came wired with the outboard thru the battery switch and I have left it that way. It is generally not an issue as long as you do not start playing with the switch after starting your outboard. I know when I first bought my boat, there is a tendency to play with that switch after you start the outboard. What happens is that when getting ready to go out of the marina, you get everything set up and then outboard is started and then you decide that the last time I had the switch to battery 1, so I now charge to battery 2, but half the time you think about this, the outboard is already running and that's when you start playing with that battery switch rather than before you started the outboard. I believe some have indicated in past postings that the 3 way battery switch even if momentarily switching between the batteries does not cause the circuit to be momentarily completely "off" while switching...but still probably not such a great idea. That's why I leave the battery switch always in the "Both" position. It probably does not utlize the batteries in the most efficient or smart way taking benefit of both batteries but it keeps me from playing with that switch which I use to do when I first bought my boat. As far as using both batteries all the time, I can't complain. I have a measly 20 watt solar panel that charges the batteries and these batteries were on the boat at least 1 year before I bought the boat and that was back in ~ Sept/Oct 2005...so my batteries are now approximately 6 1/2 years old. The only real negative for me leaving the switch always in the "Both" position is I guess if I either had a real hard time starting my outboard (which never happens) or I left a light on, then I guess both and not one battery could wind up dead...and then I would have no reserve. But my outboard would still work and so would my portable VHF. Just would not have night lights until batteries were replaced.
I guess one thing to mention is that after purchasing a new (used) boat and getting initially use to setting it up, it pays to get into a sort of set routine - form good habits as to how you set up each time and also shutdown procedures as well. For example, forming a good habit of always running the fingers over the switch panel to ensure all circuits are off. things like that will help ensure long life to your batteries.

Edited by - on

glivs
Admiral

Members Avatar

USA
836 Posts

Response Posted - 04/07/2011 : 04:44:32

I agree, our northern sailing season is far too short to waste, but getting outside projects done during the off season is sometimes a bit challenging.

Bruce,as for a switch in line with the engine - I understand and agree. As Dave was alluding too, the direct connection provides no security. Personally I'm not concerned, our bay/marina are great, but was just thinking ahead to when I purchase a new outboard or (heaven forbid) I have to sell my boat. I haven't found it again, but I recall a few years back, Leon S. posted a schematic that included a keyed switch for security. I suspect your concerns are far more probable than any other scenario, however.

As to theft in our mooring area....we did have a major problem a couple of summers ago. Several (5-6) dingies were cut free over a two-week period which caused quite a rush on cabling and locks. Someone finally caught the culprit late one night, however, transported him to a nearby pond and turned him loose. He hasn't been back yet.

Edit: Perhaps I should add the would be thief turned out to be a young muskrat with a liking for dock lines!

Edited by - glivs on 04/07/2011 14:02:00

Happy D
Admiral

Members Avatar

921 Posts

Response Posted - 04/08/2011 : 16:11:26

I think you'd have a really hard time sealing off the compartment so the hydrogen didn't get out. You'd never be able to do it so don't worry about it.

Edited by - on

Voyager
Master Marine Consultant

Members Avatar

USA
5379 Posts

Response Posted - 04/08/2011 : 21:15:02

So you get a new boat and it's full of stuff to fiddle around with. And you're running the engine, you're flipping the lights on and off, and you wonder - what the heck does this switch do?
So I blew the regulator and it boiled the battery.
I bought the repair manual for the Honda, so then I replaced the regulator and the battery.
Next season, I removed the switch from the engine circuit and placed a it with high amperage fuse.
I kept the switch in line with the panel.
Live and learn

Edited by - on

Topic

New Topic

Topic Locked

Printer Friendly

Jump To:

Association Forum

Notice: The advice given on this site is based upon individual or quoted experience, yours may differ.
The Officers, Staff and members of this site only provide information based upon the concept that anyone utilizing this information does so at their own risk and holds harmless all contributors to this site.