DC Electrical Questions

[Fred Koehlmann]

I am currently working on setting up our new DC electrical system to the point where we can launch this year. Of our previous 4Ds one died last season and we were not happy with them being set up as separate banks. In the end we really just used them as one bank(until the one of them died).

So this season we have replaced them with four Interstate 6 volts, which even ends up giving us more total amps than we had before. At the moment I'm just focusing on getting bank #1 set up, so that we can power the engine and get to our slip.In my wiring work I have some questions:

1) I'm adding both a positive and negative bus bar, instead of having everything wired direct to the batteries as it was. The bus bar comes with a nut and lock washer. The lock washer is just small enough in diameter that is slips partly into the hole of the cable lug. I'm thinking that I should be putting a washer in between the lock washer and the lug, so that the lock wash lies flat, but what sort of washer (is stainless OK, is there such a thing as copper or tinned washers)?

2) The charger (Professional Mariner Flyback 20-3 Alltech Series) has the #2 and #3 DC out terminals joined together. If I am currently going to have only one bank (until I get the spare one worked out), should I be joining #1, #2 and #3, so that all are set as a single DC source? [I assume this is the much maligned charger discussed elsewhere in the forum, but for now it seems to work and it'll get me into the water.]

3) In reviewing my existing wiring I noticed that the windlass positive was not hooked up to the common, but only to battery #2 on the 1-2-Both-Off switch! The owner's manual shows it as being on the common. I'm planning on putting it on the common as per the manual. Any reason why it was setup the other way?

4) From what I can tell our alternator is going to the starter instead of the batteries. My problem is that I can't even see the starter from the aft cabin or from the top and forward access areas. So disconnecting it from the starter is going to be problematic for me. I'd like to have the alternator charge the main bank directly. That said, is it as simple as taking the red line and feeding it to the positive bus bar for the main bank?

Much thanks, Fred.

[Stu Jackson]

1.   The washer is above the lug and will be providing the pressure required, not an electrical issue.  No problem.

2.   Flyback charger?  Fred, get rid of it.  NOW!  http://c34.org/bbs/index.php/topic,5078.msg43151.html#msg43151

3.   Only reason was to limit its use to that particular bank.  My guess is that you'll only use the windlass when the engine is on anyway.  It's your option as to which bank you should use, but IIRC Maine Sail suggests using the house bank anyway.  If you put it on the C post, it's your choice based on the switch position.  If you wire it to your house positive with its own I/O switch (and fuse it properly) then that's another option.

4.  From the "Electrical 101" topic  ---  

OEM 1-2-B Switch Wiring History  http://c34.org/bbs/index.php/topic,4949.msg30101.html#msg30101 which explains your OEM wiring.  You have to remove the jumper between the AO and the starter.   If you can't see it, then drop the alternator, it will become clearer.  Dropping the alternator will allow you to rewire it easier, too.  BE VERY CAREFUL HERE:  You need a fuse between the alternator output (AO) and the house bank, at the house bank.  We also recommend a I/O switch, too, because once connected it's always LIVE!!!  I take the fuse out when working on the engine electricals,  since I haven't installed my I/O switch yet.

Basic Battery Wiring Diagrams  This is a very good basic primer for boat system wiring: http://c34.org/bbs/index.php/topic,6604.0.html

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)
http://forums.catalina.sailboatowners.com/showthread.php?t=137615

These explain what you're trying to do and in conjunction with the first explanation in this #4, how you should wire it.  Are you going to continue to use the OEM alternator with internal regulation?  Using the OEM alternator will "allow" you to continue to use the #4 wire AO, however, you might want to consider replacing it with #2 wire now in case you upsize your alternator int he future.  Don't forget to upsize or parallel the negative, too.

[Roc]

Hi Fred,
You can get good access to the rear of the engine if you take off this cabinet panel.  I changed how mine is mounted by putting screws in from the outside with finishing washers.  You can see the screws, but it's no different than the panels hiding the fuel tank and water tank, where the screws are also visible.  This picture is before I changed to the outside screws.

[Fred Koehlmann]

Thanks Stu,

I did look at those links and they in a large part informed me on what I am currently working on.

I figure my current alternator layout is like your Figure #2 on "http://c34.org/bbs/index.php/topic,4949.0.html" and I do want it to ultimately look like Figure 3#, wired direct to the batteries.You mention about the negative is a good reminder that there are other wires to look at that I forgot about like the sense wire. Although I thought that if the black was going to the "big" black ground from the starter which is the one I believe I see connecting to the battery ground, that it would be OK. But having it independently and directly go to the battery does make more sense and does keep things cleaner. Yes, good point about a separate or dedicated switch.

Yes, I did mention that I recognized the Flyback as the charger of concern, but unless i want to spend the entire season out of the water, I need to launch with something. It has been on the boat for ten years without issue, and I'm hoping that it will work for a few more months until I can replace it. But the question was about how to wire it for a single bank, until I can get things changed around. Also we never leave the shore power on when we leave the boat.

Roc: I'm not sure where your starter is but mine appears to be somewhere on the aft head side down below. Even if i removed the top hatch piece in the aft cabin, I couldn't see it. I uses mirror from below the exhaust pipes to see where the big red and black cables disappeared. I didn't see any other lines. Of course the fact that everything is spray painted an even grey colour also doesn't help perception, especially with progressive lenses on your nose! I'm wondering if I disconnect the lines from the alternator, and cap them off to the side, whether that is OK? Seems not to safe to me.

[Stu Jackson]

1.  ...Although I thought that if the black was going to the "big" black ground from the starter which is the one I believe I see connecting to the battery ground, that it would be OK. But having it independently and directly go to the battery does make more sense and does keep things cleaner. Yes, good point about a separate or dedicated switch.

2.   ...But the question was about how to wire it for a single bank, until I can get things changed around. Also we never leave the shore power on when we leave the boat.

3.   ...I'm wondering if I disconnect the lines from the alternator, and cap them off to the side, whether that is OK? Seems not to safe to me.

1.  A "black ground from the starter" doesn't sound right.  The starter should be wired with a big RED wire from the C post of the switch.  It may have a lot of black tape around the end of it.  The main black engine ground, from the battery box negatives should be on the aft port bolt on the back of the engine.

2.  Single bank charging from the Flyback?  You didn't mention if you were going to install an echo charger or ACR.  If so, just disconnect the charger from the second reserve bank.  If not, and since you don't leave the boat with the charger on (good for you!) then use the BOTH position on the switch to charge both banks with only the house bank connected to the charger.  Same with the alternator.

3.  When working on them, yes, just turn the switch OFF, too.  Follow the electrons......from the batteries.  I was on a Mark II last week, and agree, even with Roc's improvements, you simply can't see in there unless you drop the alternator.

Good luck.

[chuck53]

Hi Fred,
You can get good access to the rear of the engine if you take off this cabinet panel.  I changed how mine is mounted by putting screws in from the outside with finishing washers.  You can see the screws, but it's no different than the panels hiding the fuel tank and water tank, where the screws are also visible.  This picture is before I changed to the outside screws.

Roc, I never thought about engine access thru this shelf.  How difficult is it to take this shelf off?

[Solstice]

I am currently working on setting up our new DC electrical system to the point where we can launch this year. Of our previous 4Ds one died last season and we were not happy with them being set up as separate banks. In the end we really just used them as one bank(until the one of them died).

So this season we have replaced them with four Interstate 6 volts, which even ends up giving us more total amps than we had before. At the moment I'm just focusing on getting bank #1 set up, so that we can power the engine and get to our slip.In my wiring work I have some questions:

1) I'm adding both a positive and negative bus bar, instead of having everything wired direct to the batteries as it was. The bus bar comes with a nut and lock washer. The lock washer is just small enough in diameter that is slips partly into the hole of the cable lug. I'm thinking that I should be putting a washer in between the lock washer and the lug, so that the lock wash lies flat, but what sort of washer (is stainless OK, is there such a thing as copper or tinned washers)?

2) The charger (Professional Mariner Flyback 20-3 Alltech Series) has the #2 and #3 DC out terminals joined together. If I am currently going to have only one bank (until I get the spare one worked out), should I be joining #1, #2 and #3, so that all are set as a single DC source? [I assume this is the much maligned charger discussed elsewhere in the forum, but for now it seems to work and it'll get me into the water.]

3) In reviewing my existing wiring I noticed that the windlass positive was not hooked up to the common, but only to battery #2 on the 1-2-Both-Off switch! The owner's manual shows it as being on the common. I'm planning on putting it on the common as per the manual. Any reason why it was setup the other way?

4) From what I can tell our alternator is going to the starter instead of the batteries. My problem is that I can't even see the starter from the aft cabin or from the top and forward access areas. So disconnecting it from the starter is going to be problematic for me. I'd like to have the alternator charge the main bank directly. That said, is it as simple as taking the red line and feeding it to the positive bus bar for the main bank?

Much thanks, Fred.

Hi Fred,
One of the first things I did when taking delivery of my new boat was rewire. I had the same issue with access to the Starter. After consulting with Maine Sail, I did not remove that wire, but used Rescue Tape to isolate the lug (MS suggested Heat Shrink tubing, but I wanted to be able to have the option of using it should the need ever arise), then cable tied the wire along the Battery cables that also attach to the Starter. Finally I labeled the wire so someone other than me will not what it is.
Hope this helps...
Jon Vez
Solstice 355 #17

[Fred Koehlmann]

Stu:
1. Thanks, I'll try to get a better look this weekend. That was an assumption on my part since I can only see both the red and black disappearing into the same area. The red from the starter is at the C post.

2. At this point all 4Ds are off the boat, and we only have one (1) bank of four 6 volts. I hope that by the summer I'll have the second bank in, which will probably be just a single 12 volt (as a spare/backup). I still need to determine the location, but at that time I was planning on using an ACR. I was also hoping to have a new charger by then. This is why for now I need to wire the charger to only one bank. The online instruction information does not suggest anything other than for wiring three banks. Since in its recent state (when I use to have two banks) the charger had the #2 & #3 post bridged together, I was extrapolating that if I use it on only one that I would have to bridge all three posts. (sort of like what Mainsail mentions doing on the Sterling charger install). Just that since I don't have any documentation, I was looking for a more educated guess than my own.

3. Since I'm trying to get into the water this weekend, I may have to wait until after launch to look at this. I figure as long as I have changed anything and never take my switch off of #1, I should get to my slip just fine. Once there I should have time to drop the alternator and take a better peek at things.

Jon: Thanks, that what I wondering about. It just seemed kind of unsafe if it ever came loose, but I like the route that you took. I may just do the same.

Roc/Chuck: That shelf does provide easy access, but really only to the top aft section of the engine. To get lower, you need to go at it from under the aft berth. I suppose if I was daring I would look at removing the entire aft box (last resort).

[Roc]

It's not the shelf I'm talking about.  That stays were it is.  It's the panel directly below the shelf (shown in the picture).  There are screws set into that panel from inside.  That's what give's it a 'finished' look from the factory (no screws shown).  If you take those screws out, that whole panel will come off.  You might need to run a razor blade along the two vertical ends because the varnish might stop you from pulling it out.  The rounded corners stay, it's the flat panel that will come off.  To re-install, you can screw it back on with the original screws from the inside.  Or you can do what I did, drill new holes straight through the wood panel, into the wood attached to the fiberglass.  Get finishing washers and oval head screws (3 on each side), and now you can easily remove that panel to access the rear of the engine.  Makes changing the ATF much easier too!  If you take that panel off, and take out the horizontal panel covering the shaft and bilge area, you have open access to the rear of the engine (remember, the shelf is still there, you don't take that off).

[Fred Koehlmann]

Thanks Roc! I do understand now. Its the rear panel you're talking about. Yes, that would probably help a lot, and its good to know that it can easily be removed. Will look at it this weekend.

[John Sheehan]

Fred,

The whole cabinet in the aft is only held on with six screws.  They are located just under the flip top.  One of them is visible on the left side in the picture.  You may need to "tap" the upper part of the cabinet with a rubber hammer since it may be stuck to the varnish.  Keep track of where the screws came from as some are different sizes.  After you remove the cover over the shaft log the whole cabinet should come out giving you very good access to the aft of the engine.


John

[Stu Jackson]

Good observation, John.  The advantage of the Mark IIs is that the enclosure is wooden.  On the Mark Is the vertical part of the enclosure is fiberglass and thus not removable. On both, IIRC, the top is Formica with a teak edge.