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.
A chance observation - arrived my planned anchorage nearly 1 hr after sunset, i.e. it was dark - no artificial lighting. Navigation lights were still on as I prepared to drop the anchor. I began to lower the anchor into the water and then pulled a few feet of chain back in to let the boat's forward motion come to a stop when I noticed that where the chain (now wet) touched the pulpit the side of the links would light up in white/blue light. There was no similar response with the chain touching the sides of the bow roller. Similarly if I was careful not to let the chain touch the pulpit there was no light. I suspect there must be a short in the wiring leading to the bow navigation lights inside the pulpit but haven't thought through yet how to diagnose. Anyone ever encounter something similar?
It would seem the bulb socket in the bow light on the rail is electrically contacting metal that is attached to the rail, and the charge is generating a phosphorescent glow in the water on the chain. It also could be worn insulation on a wire running through the pulpit. I tend to doubt there’s significant current flow through the chain, since there is nothing closing the circuit from there to the battery—you could test that with a meter. But now I’ve said more than I know.
Dave Bristle Association "Port Captain" for Mystic, CT PO of 1985 C-25 SR/FK #5032 Passage, ex-OUPV Now on Eastern 27 Sarge (but still sailing when I can). Passage, Mystic, and Sarge--click to enlarge.
Dave...I'm slow to respond but wanted to get some measurements before doing so.
To start, the navigation lights function as expected.
So...I ran a length of wire between the neg lead on the multi-meter back to a negative bus bar in the cabin and then simply used the positive lead of the multi-meter to "explore". The results were surprising, at least to me. Important - measurements were similar whether taken on the back side of the light fixture (SS) or anywhere along the SS railing down to the deck.
House battery switch ON, all panel switches OFF: Voltage at the battery using the test wire setup: 13.2V (w/ my 5V solar panel on a grey day); 13.4V with multi-meter alone...a 1.5% drop due to the long test lead.
Bow pulpit: Navigation lights switch OFF: 0.3V; switch ON: 6.9V
Stern pushpit: Nav lights switch OFF: 0.3V; switch ON: 11.5V
What??? Looks like another todo item come next spring.
First of all, the solar panel, I guess you mean a 5 watt panel since a 5 volt panel, the electricity would never flow to the batteries during charging. Typically, solar panels regardless of wattage, will charge the battery with a voltage greater than the battery voltage , probably around 14-16 volts. Then the batteries can get charged with a 5 watt, etc charging rate.
The two ways that I can think of and I am sure there are addl ways for a residual voltage/battery loss with switches off are: (1) Sometimes a PO may have hooked up addl wires behind the switch panel and some used a sort of gang connector that allows 2 wire feeds to be connected. If that has been used for any connections behind the panel, sometimes one of the terminals or wires comes extremely close to other terminals wres behind the panel. In my case, my VHF radio would work even when the panel switch was off. Great for immediate VHF service but not so hot for unsat wiring. That was one reason I added another switch panel for my boat, to get rid of some of the double terminal hookups on the exiting panel. (2) But this is what I suspect may be your issue: A solar panel is great for charging a battery on sunny days but a you can actually have some residual charge lost thru the wires going to the panel as panels will minutely discharge electricity at night and during overcast days. Those that have 10 watt and higher solar panels will generally install a solar controller so that the batteries are not overcharged but a solar controller also prevents residual discharging back out the solar panel. Some 10 watt and higher panels have built in diodes to prevent that discharge even if they do not have a solar controller. Since a 5 watt solar panel charges at such a slow and low rate, batteries will not get overcharged and so no controller is installed. If that is the case, it is possible since you mentioned it was a grey day, that the panel was actually slightly discharging. To check that is easy enough - Just disconnect one of your panel wire leads and then see if you still have .3V registered on your meter. If you do, then you can at least rule out the discharge from the panel on grey, overcast or night time conditions.
Thanks Larry, yes it is a 5W solar panel. And yes the voltage measurable when all panel switches are off is a concern. However, my sailing season ends in a couple of weeks so this will have to wait until I'm on the hard but as you suggest I need to check the system carefully with and without the solar panel in the loop. Easily done, just need a little time. FWIW....ironically I have the same BEP 8 circuit breaker panel as you that I found on e-Bay several years ago for a small fraction of the list price because the packaging was damaged. Also my solar panel is wired through a PWM controller rated for a 30W panel although my electrical needs to date have not warranted going with a larger panel. More later...
Gerry, You do have a solar controller in the circuit ! Well, then maybe the residual loss is not thru the panel since the controller would prevent that. Still, worth a try to find out since it is an easy test.
Wow ! You have the same circuit panel (BEP). It is an Australian or New Zealand Mfr and so not as popular over here. But works fine and i like the design. Where I located it on the fiberglass in front of the sink, I needed a panel that had it's inner works with a small footprint so that it did not make contact with the sink bowl. The BEP panel was just a bit smaller in footprint that some of the competition and so that is one reason i went with it.
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.