22D DC Ground Question

[Merilintu]

New owner with a 22D that came rigged with a panel for 2 batteries, but currently only has 1. There are 8 breakers, a power meter, and the 1/2/Both switch all on the panel. I have taken the panel off, but can only get it an inch or 2 away from the liner before getting serious resistance from the wiring behind. I am afraid I am going to pull something loose. Right now, all electrics are working fine, but I need to add a new circuit.

The positive side of all circuits seems to be fairly tidy, and screwed down nicely to the panel. There is an unused breaker available, and accessible. My question is, where the heck is the negative bus on this boat? I can't see anything behind the panel, but can only get it an inch or so away from the liner. I have been all through the lockers and engine compartment, and found nothing. It looks like all existing wiring is in the cabin top and inaccessible. I found the grounds for the bonding system in the bilge where it ties to the exterior plate on the keel, but I don't want to tie to that. There's a PILOT light that's on anytime the power is turn on. It can't be kosher to tie a ground to that, can it?

Any ideas? I'm just adding a VHF and a few USB ports for charging my phone and tablet. I'd take a ground from one of the cabin lights, if I could get to them.....

Thanks in advance for any guidance!

Roger
S/V Merilintu

[Russell]

Cape Dory while they built good boats in general, were not so good on the wiring side. Most likely your negative bus is all the negatives brought together and twisted together then soldered in a big ugly lump. If you are going to be mucking about in there, I recommend buying a proper bus bar and fixing it.

[Steve Laume]

Russel is right on as usual. The soldered mass might be an improvement over what they did on my boat. Look for an octopus on the volt meter. This is where all my grounds terminated.

You definitely don't want to tie in to a random wire for grounding. This could overload the return wire. Properly grounding your boat at the panel is not that difficult. Get a buss bar, a good crimper, a bunch of terminal ends some spare wire and some wire ties. Mount the buss bar and take all of your grounds to it. You will never regret doing this.

If your panel is that hard to get to under normal conditions, think of what you might need to go through if you had a problem while out sailing. It is a very good thing to get familiar with what is going on back there and clean things up so if you ever do have problems you will be better able to deal with them, Steve.

[M. R. Bober]

Oh Roger, now that you own a Cape Dory you have become aware of our dirty little secret, the electrical "system." Nearly anything you do to modify it will, probably, be an improvement. Someone installed that wiring and they needed some room to do it. Is the panel restrained by wire length or is the panel (wood) caught by the fiberglass surround? I have found some wires that were glassed into the headliner (CD27), and other similar atrocities.

However there is good news. You will become an expert on the subject of 12VDC. Get a decent book or website on the subject. Pick up a few simple tools, and start making your world a better place.

Welcome aboard.

Mitchell Bober
Sunny Lancaster, (Where we charge ahead slowly.) VA

[hilbert]

You can see the big ugly lump lurking in the bottom middle of the pile, next to Waldo.


For more fun, this rust was the grounding bus next to the engine.


On the `positive` side, the ground was the more reliable side of the circuits

[Oswego John]

Offering a FYI on the first picture showing the "Ugly lump" of negatives.

Although there are many negatives in the picture, there is one positive (pun intended) that I spotted.

Notice the red and black conductors on the left side of the picture. They are twisted together to negate EMF forces. We were taught that this is proper procedure when installing wiring for DC power, especially when in close proximity to magnetic sensing direction devices or other susceptible nav and communucation equipment.

Otherwise, some people would call this picture an electrical "rat's nest".

FWIW
O J

[Merilintu]

Thanks for the replies. I don't feel so bad after seeing those photos. Mine is much better than that

I put a multimeter on the battery and measured amperage. I do have a stray 3.5 amp load when the master battery switch is on. The boat "appears" almost untouched since it was built. There were never any instruments installed...The complete inventory of electrical items that I know about is:

4 cabin lights
2 running lights
anchor light
foredeck light
Pilot light and voltmeter with light on the panel
Yanmar diesel

So I am really confused about where the stray load is coming from. I am very hesitant to start tearing apart the DC system because EVERYTHING WORKS GREAT..... I've left the boat untended for more than a week(with master battery switch off) and the battery holds it's charge just fine. But I spent my first night on board and left the anchor light on all night, and the battery did read the lowest
I've seen it since I got the boat. It was still in the green, and the engine starts on about the 2nd rotation of the starter, so I don't think that will ever be a problem.

Anyone have any suggestions short of pulling each circuit off to see where the load is coming from?

TIA

Roger
S/V Merilintu

[Oswego John]

Merlintu,

Buy, borrow or rent, whatever it takes, a clamp-on meter. Wrap it around each circuit's hot or pos. wire. In most cases it will be a red conductor that is connected to a fuse or breaker.

With the master switch turned on and every electrical device locally turned off, read the amp flow on each circuit. Don't forget any inline fused bilge pump.

Good luck,

O J

[Russell]

3.5 amps is a LOT.

Ok, this is the obvious question, and I am entirely sure you thought of this or know it, but we all make dumb mistakes, so asking it anyway. You did not per change have a battery charger hooked up when you saw that current (and perhaps the leads reversed, amps going IN rather then out?).

None of the devices you listed should individually draw that much power, something is definaely not right (and dont rule out the fact it might be your multimeter).

OJs advice to use a camp on meter is good, but DC clamp on meters are not something you find at Home Depot (AC sure, but not DC). You can find them online, but they tend to be spendy, especially if you want want that can measure signifigant amps (which you want if you are going to bother getting one in my opinion). But really, other then getting the clamp on meter, you are indeed stuck disconnecting wire one at a time and rechecking, cheaper but more time consuming. But considering how few circuits you have, that really isnt all that daunting, in your shoes I would probably opt for that.

But first, before anything else, borrow a friends multimeter and check it against yours, just in case yours is faulty, 3.5 amps is a lot I am suspicious.

[Merilintu]

Never underestimate the possibility that I may have no idea what I am doing!

I thought it was unusual, too, and I am now questioning how I had the meter set. It is a really
nice Fluke, and it's far more likely that I made a mistake than there being a problem with it.

There is no battery charger or electric bilge pump on the boat, and her bilge is amazing dry,
with just a tiny weep from the stuffing box.

So I will double check my multimeter setup 101, and give her another shot this weekend.

I think I am doing positive lead in the 10A hole, common in the neg hole, and then putting
positive lead on the battery terminal and common on the positive cable(disconnected, of course).

Thanks for the healthy skepticism. I'd much rather find out I screwed up before pulling
the whole system apart!

Roger

S/V Merilintu

[moctrams]

I use a Clamp on ampmeter to measure "leakage". This is the proper way when using a Fluke.

1.Turn on the digital multimeter. Most digital systems run a self-check before they are ready for use. Allow a minute for the meter to complete its testing.

2.Set the function selector to read amps from battery power or alternating current. The function setting "A~" measures alternating current in amps, or AAC; "A=" measures direct current in amps, or ADC.

3.Set the range so the maximum is well above the highest reading expected. This will protect the meter from getting overloaded. If you overshoot the range and cannot get a reading, set it lower.

4.Connect the leads to the proper terminals for measuring current. Connect the black lead to the "COM," or common terminal. Connect the red lead to a terminal marked for low- or high-current measuring. The low-reading terminal may be identified as "300mA." This would give readings in milliamps; 1 milliamp equals .001 amps. Multiply by 1,000 to get the figure in amps.

5.Break into the circuit to measure its current. Set the red probe on one open end and the black probe on the other. This may require cutting a wire to get the probes between the circulating current. The idea is to let the current flow through the digital multimeter to allow it to get a reading.

[Merilintu]

First, thanks to Russell for calling me out, as I obviously had the meter set wrong on the first go around. I tried again this morning and was able to measure the current load for each circuit from the battery. There is no stray load. I did learn that I have 2 different bulbs in my cabin lights:

GE 94 draws 1.0 amps
GE 1142 draws 1.3 amps

They both "appear" to give the same amount of light, but I've been experimenting with 2 other LED replacements over the V berth, which
are .2 amps and .25 amps, and give a much brighter, but whiter, light. So goodbye to the two remaining GE incandescent bulbs.

Running lights are Aqua Signal and use those annoying festoon bulbs. 1.5 amps for bow and stern together. Has anyone found an LED
festoon replacement bulb?

My new VHF pulls a miserly .4 amps on receive mode, but almost 5 amps on 25W transmit. I got a response from 7 miles loud and clear, so I guess it works.

Now the mystery: My deck light pulls ,65 amps, but my anchor light shows no load at all when I turn it on...but it's working. I had to climb in the dink and row far enough out to see that it's on, but the ammeter says 0.00. AND when I turn it on and off, I get a crackling on a portable FM radio that I had on listening to NPR. I am guessing this means there is some kind of short in the mast? No other circuits in the boat cause this FM crackling. Any ideas on next steps? I plan on overnighting a lot, so I need a working anchor light that's not going to drain the battery.

I also did the test for ground leaks, and luckily there are none.

All in all, I'm happy. But the anchor light draw was what started this whole search in the first place, and obviously something's not right.

I'd appreciate any ideas! TIA!

[Russell]

Running lights are Aqua Signal and use those annoying festoon bulbs. 1.5 amps for bow and stern together. Has anyone found an LED
festoon replacement bulb?

Yes, I was able to buy a DrLED brand festoon bulb last year at West Marine that went into an Aqua Signal housing.

[hilbert]

Running lights are Aqua Signal and use those annoying festoon bulbs. 1.5 amps for bow and stern together. Has anyone found an LED
festoon replacement bulb?

Roger, check out http://store.marinebeam.com/led-navigation-bulbs.html. Their bulbs use constant current circuits. See their explanation for why this is desirable at http://store.marinebeam.com/whyounetokna.html. I have no personal interest in their web site, except that they have treated me well.

I was at the boat and took a close up of the "ugly lump"

I don't feel so bad after seeing those photos. Mine is much better than that

I have photos that can make everybody on the board feel better about their boats!