Electrical system rehab

Ol' Coot · Post by **Ol' Coot** » Sat Mar 12, 2005 2:06 pm

Hi All,

I'm starting to think about a total rehabilitaion of the electrical system in my '79 Tartan. It's got pretty much what I think is the original setup, with a few additional items courtesy of the prior owner. There is a single battery with master switch, distribution panel with running lights, spreader lights, cabin lights, and a couple of auxiliary circuit with radio, loran, tape player, etc. the bilge pump is on its own circuit so it can be left "hot" with the rest of the system shut down.

I'd like to upgrade to a dedicated starting battery and 1 or 2 house batteries, maybe AGMs. The house battery, or batteries, obviously would pick up the other items in addition to upgraded cabin lights, fixed GPS, instrumentation, a place to plug in my notebook PC and hopefully a tiller pilot some time in the future. I have the luxury of docking in a marina, so a full time connection to shore power and a quality charging system are also possibilities. Does anyone have thoughts regarding the use of solar charging as an alternative to shore power charging? I'm just not thrilled at his point with leaving the electrical system continuously connected to shore power.

Also, I'm thinking about installing standard grey plastic wiring conduit to a) protect the wires in long runs through cockpit lockers and behind cabin trim and b) separate power carrying wires from antenna leads, etc. Is there any known issue with this idea?

Thanks,
Kevin

JonnyBoats · Post by **JonnyBoats** » Sat Mar 12, 2005 5:31 pm

I'm thinking about installing standard grey plastic wiring conduit

One thing to be careful of with this is trapping water in the conduit, other than that it is a great idea. You can deal with the water issue by drilling holes in the conduit to let any water which might enter simply run out.

bcooke · Post by **bcooke** » Sat Mar 12, 2005 6:10 pm

Hi Kevin,

Your system plan sounds pretty good to me.

Normally I am a fan of solar power but in your case I am not so sure. I have never had the opportunity to plug in after every sail and I don't like using the engine to charge the system so solar is always part of my charging system. Wind generators are great but the winds in the Northeast during cruising season are too light I think and the fact that they are noisy rules them out for me.

Now, unless you foresee spending a lot of time away from shore power I think I would stick with it. With a little forethought, and a good circuit breaker I think being plugged in for longer periods of time would be okay. You could set up the charger on a timer if you were going to be away for awhile and didn't want to monitor the charging. If all you were looking for was a trickle charge for the engine battery then maybe one of those "throw down/ fold up " solar panels would be called for.

Solar works for me because I keep the electrical draw to a minimum... and nothing else really works in my situation (I mentioned the lack of wind and running the engine already). Solar panels are big, expensive, and some would say not too attractive... oh, and they don't produce very much unless you constantly monitor them and reposition them to face directly into the sun. On the plus side they are quiet and low maintenance (unless you drop something onto them).

I am sure you will get a lot of opinions on this topic.

-Britton

Figment · Post by **Figment** » Sat Mar 12, 2005 9:51 pm

Unless you splurge on 12v refrigeration or an anchor windlass or some other mega-hungry device, your battery bank won't need to be anything outrageous. I think, therefore, that you probably won't need to leave the shorepower connected continuously if you don't want to. When you dock after a daysail, connect the shorepower while you do your washdown, etc. That 30 minutes should be adequate to replenish whatever the engine hasn't. After a longer cruise, an overnight connection may be required.
Solar charging has come a long way in recent years.... IF you can find a handy place to locate the panels. That always seems to be the dealbreaker with solars.
Ditto for the new multistage smart charging systems. As soon as I can stop spending my boat-bucks on structural repairs, I'll be shopping for one myself.

Does plastic conduit do anything to kill EMF? Enough to make a noticeable difference regarding antenna cables?
I run my wires in twisted pairs (or use the pre-twisted cable) to minimize this.

Nathan did a dandy rewiring job on Dasien last year, as I recall. I'm sure he'll chime in with some good thoughts.

bcooke · Post by **bcooke** » Sat Mar 12, 2005 10:24 pm

Does plastic conduit do anything to kill EMF? Enough to make a noticeable difference regarding antenna cables?

Mike, I thought EMF refered to Electro Motive Force ... which is measured in Volts... (E=I/R). Do you mean something else? And by antenna cables do you mean coaxial cable?

I think the conduit is really only useful to contain the wires in a bundle and protect the bundle from abrasion. Aesthetically it looks a little neater too.

And Nathan, did you hide your full description of your re-wiring job on your website or did I miss it?

-Britton

Post by **dasein668** » Sat Mar 12, 2005 10:27 pm

I had a solar panel for the first couple of years we had the boat. Worked fine and did a good job of keeping the batteries topped up, but as Britton points out, it requires constant vigilance to get anything close to rated amp-hours out of the thing. Solar really is designed for stationary installations where they will be set at an optimum angle to the sun, or even better yet, track the sun automatically.

When we rewired last winter I didn't reinstall the solar panel. Turns out I didn't miss it much either. Running the engine on and off the mooring when I didn't sail on and off or on early morning starts (pre-wind) of cruises kept up with my modest electrical needs.

Your list of electrical loads is pretty short so I suspect that you will find, as Figment said, that you don't need alot of topping up most of the time. With a couple of AGMs for the house bank you should easily be able to come up with 200ah of capacity. More if you can use larger than Group 24. That's alot of capacity with respect to your list of power-users.

You can see what I did last year here: Dasein's Rewiring

Post by **dasein668** » Sat Mar 12, 2005 10:37 pm

bcooke wrote:Mike, I thought EMF refered to Electro Motive Force ...

Oh, jeez... I thought EMF stood for "Epsom Mad Funkers" that 90s band that sang "Unbelievable."

I can understand wanting to kill that! hehe

Figment · Post by **Figment** » Sat Mar 12, 2005 10:48 pm

ElectroMagnetic Field. Twisting the pairs of wires together causes the individual fields to cancel each other out so that compasses, radios, and other sensitive devices may happily coexist.

I wasn't trying to talk Kevin out of doing the conduit. Just remember to use polyester or some other synthetic for the pull-cord. Cotton cords will rot and snap mid-project in about 5 years.

Epsom Mad Funkers. Wow. A thousand "Whose Line Is It Anyway" points to Nathan for pulling that rabbit out of the hat.

Post by **dasein668** » Sat Mar 12, 2005 11:22 pm

Figment wrote:Epsom Mad Funkers. Wow. A thousand "Whose Line Is It Anyway" points to Nathan for pulling that rabbit out of the hat.

Hehe. I'm a veritable fount of useless knowledge! Well... maybe "knowledge" isn't the word I'm looking for...

Post by **Tim** » Sun Mar 13, 2005 10:41 am

My own thoughts on conduit for wiring runs would be to limit the conduit usage to those areas where the wire might realistically be damaged (such as through the working part of a cockpit locker), or if you need to hide a section of visible wiring somewhere in the cabin, but I wouldn't use it for general runs. If something goes wrong, you can't access any of the wiring, nor is it easy to include fixtures along the middle of the conduit run, unless you plan carefully and add openings through which to pull the wire.

The idea of pulling new wires through existing conduit is always nice in theory, but in practice, the conduit ends up somehow overstuffed to begin with, negating any chance of running something new inside.

I prefer bundles run in out-of-the-way places, all secured with cable clamps or plastic wire ties in those neat little holders. It is important, though, to protect the wiring wherever it is run--hence the conduit in the lockers and such, as you originally suggested. If you can run the wiring up high and out of the way, you may not need the conduit. I found I was able to keep all my wiring clear from immediate danger wherever it was run. There are a few places where I might have done better. There's always room for improvement.

And avoid any temptation to run any wires through the bilge. Don't. There is always another way. Only the bilge pump wiring should be there, and it sure would be nice to avoid even that!

Note that a pair of inexpensive 6-volt Trojan T-105s, wired in series, will supply you with about 220 Ah of deep-cycle power, for far less cost than any of the alternatives (typically about $65 per battery). I have been a complete convert to 6 volt golfcart batteries; they have worked extremely well for me. Steady, reliable power and efficient charging. My own battery banks include a pair of T-105s for the house, which is overabundant for my electrical needs (and is how I planned it...), and a single starting battery, isolated from the house bank. I run a 3-stage external regulator and large frame alternator for charging.

bcooke · Post by **bcooke** » Sun Mar 13, 2005 1:33 pm

Epsom Mad Funkers

Surrounded by Cyber experts I learn something new every day . Now who are they again?...

This thread got me thinking and I started drawing out some possibilities for my own electrical overhaul next winter. I was wondering about those golf cart batteries and with the positive endorsement that is probably the way I will go. And thanks Nathan, I must have totally blanked that one out. How do you like your system today?

Twisting wires. I will have to try that. Interesting that in the airplanes I work on twisting wires is not normally practiced. The magnetic compasses in the cockpits are also notoriously inaccurate so maybe there is a connection?

Here is a weird thing that is totally off topic but maybe you geniuses can explain it to me. At my work table in the basement (beautiful thing basements... it can snow all it wants and I can still get something done. Too bad those smells migrate upstairs and I catch so much hell for it!) there is a bar with about ten electrical outlets wired in. My radio hanging on the wall normally gets pretty poor reception but when I plug in my overhead flourescent light to the outlet bar the radio reception suddenly improves dramatically. Why in the world does that happen?

-Britton

Post by **Tim** » Sun Mar 13, 2005 1:45 pm

Twisting wires. I don't think you have to do this to all your wiring, but it may be a smart idea if you have a lot of wiring run close to your compass. I twisted the wires that run up to the compass light, I think, but that's about it. My other wiring is far enough removed.

Of course you know the trick to chuck the ends of the wires into your drill, clamp the opposite ends somewhere, straighten/stretch the wire out and slowly run the drill to automatically twist the two wires.

bcooke · Post by **bcooke** » Sun Mar 13, 2005 4:26 pm

Of course you know the trick...

Actually I didn't but I do now. The key I imagine is to run the drill slowly. One could get carried away there...

-Britton

Figment · Post by **Figment** » Sun Mar 13, 2005 7:17 pm

Most of the original wiring runs (at least, I imagined them to be original) on #78 were twisted pairs. Even if there are no compasses or other sensitive devices around, running in twisted pairs can also help in keeping things bundled.

Tony · Post by **Tony** » Thu Mar 17, 2005 5:41 pm

OK, I'll take a stab at it:

Here is a weird thing that is totally off topic but maybe you geniuses can explain it to me. At my work table in the basement (beautiful thing basements... it can snow all it wants and I can still get something done. Too bad those smells migrate upstairs and I catch so much hell for it!) there is a bar with about ten electrical outlets wired in. My radio hanging on the wall normally gets pretty poor reception but when I plug in my overhead flourescent light to the outlet bar the radio reception suddenly improves dramatically. Why in the world does that happen?

My guess is the electrical cord to your light fixture is absorbing and re-radiating your radio signal. the electrical cord is probably very near a harmonic of the wavelength of your radio signal. Does just your chosen station improve or is it broad-spectrum improvement? Actually that's kind of funny, because fourescent lights usually make RF reception worse :-)

Tony

A30_John · Post by **A30_John** » Fri Mar 18, 2005 6:43 pm

I run a 3-stage external regulator and large frame alternator for charging.

Tim, what three-stage regulator do you use? Are you happy with it?

What is a "large frame" alternator?

Is anyone on the board using a battery combiner? I'm thinking about this one:

http://www.yandina.com/c50Info.htm

Post by **Tim** » Fri Mar 18, 2005 6:58 pm

I have the Ample Power Next Step regulator. I has worked well for me over 4 seasons now. This regulator is highly programmable, though I haven't done so. It also has diagnostics built in, and charging status. Most of its capabilities are over my head.

The higher amperage alternators tend to have a heavier casing, i.e. "large frame". I don't truly know what other differences there may be, though the larger alternators are heavy-duty and tend to be super cooled with large fans. They're well suited to external regulation (and don't have internal regulators...)

Figment · Post by **Figment** » Fri Mar 18, 2005 8:06 pm

Battery combiner!!! DAMN! I just KNEW I'd forgotten something at that super-discount west marine weekend.
It's amazing what slips your mind when the cellphone rings and your wife utters the phrase "frozen pipes".

Yes, I plan to install a battery combiner. It's a no-brainer, I think, particularly for those of us who can't justify the expense of the smart charging/monitoring devices.

Defender's big weekend sale is coming up. I'll probably grab whatever they have on the shelf.

Post by **dasein668** » Fri Mar 18, 2005 9:45 pm

I installed the Xantrex Pathmaker. I liked the fact that it had adjustable cut in, out, and overload voltage settings.

bcooke · Post by **bcooke** » Fri Mar 18, 2005 10:32 pm

Tony, I tried and it seems the reception reacts the same no matter what station is tuned in. There isn't a ground wire in the whole house I am living in so I was thinking the lights were providing a pseudo ground somehow - the theory is way over my head though.

particularly for those of us who can't justify the expense

Justify? Who tries to justify what we do? I just pass along the credit card number and try not to think about it. Nothing is too good for my baby...

-Britton

Post by **dasein668** » Fri Mar 18, 2005 10:40 pm

bcooke wrote:
particularly for those of us who can't justify the expense
Justify? Who tries to justify what we do? I just pass along the credit card number and try not to think about it. Nothing is too good for my baby...

-Britton

Ahhhh, the Lackey school of boat restoration...

Post by **Tim** » Sat Mar 19, 2005 8:25 am

What the boat wants, the boat gets.