monitoring current flow

[EscapadeCaliber40LRC]

I am looking for some source of current drain. At night, with the wind gen tied off, and the master DC and AC panels off and all direct fuses pulled, I still see .1 to .2 amps constant current flow draining, using the Heart 2000R monitor, how much current should I be seeing ? Oh and the refrig is off too. It seems like too much for just running the Heart Monitor itself. I'm thinking I have a galvanic leak somewhere and I'm trying to find it but not sure how to trouble shoot it further.

[Goodnewsboy]

What is a galvanic leak? If everything is indeed switched off, I'd say you have a plain old short circuit somewhere.

Get out your multimeter and start checking individual circuits for resistance when switched off. The leads on the load side of the circuit breakers are a good place to start. Any item that doesn't show a nice healthy high resistance in the off state is suspect. Pay particular attention to any circuit that goes up inside the mast; testing resistance both across the circuit and from each conductor to the mast itself. Sometimes the insulation on these wires will wear through.

Your problem might be a dirty terminal or a switch that has accumulated some kind of conductive crud. Sometimes the offending element can be restored by cleaning.

Have fun!

[SanderO]

Do you have any radios with an always on memory circuit?

Your monitor itself will show some load and the inverter if on and not used also has some load.

Did you measure the the draw at different locations with the monitor out of the circuit? At the batts themselves?

jef
sv shiva

[sailingdog]

Radio memory and the monitor shouldn't add up to .2 amps generally. You've got a bad circuit someplace. I've got instructions for tracing a DC-side galvanic leak posted, and I'll see if I can dig them up for you.

[sailingdog]

FOUND IT....

Originally Posted by sailingdog

Zanshin-

If you want to test to see if you have a DC-based ground leak, the test for that is rather simple. The steps for seeing if you have a DC-ground leak are as follows:

First—the preliminary diagnosis test:

1) Turn off all equipment and disconnect any solar panels
2) Disconnect the positive side of the battery banks.
3) Leave the main battery isolation switch turned on for the bank in question
4) Set the meter to VDC mode, range appropriate for your battery bank
5) Connect the meter between the positive terminal and the disconnected cable

The meter should give no reading. If it reads XX volts for your XX VDC system, one of two things is happening.

1) You've left some equipment connected and turned on. This could be a bilge pump, a power feed to a stereo for the radio's memory and clock functions, or a hard-wired fume detector.

2) If you've disconnected all the "hard-wired" equipment and still get a reading, then you've most likely got a ground leak in your boat's DC system.

The Ground Leak Check:

1) Set the meter in Ohm mode and set it to the lowest range (x1).
2) Connect the leads of the Ohm-meter (or multimeter in Ohm mode) to the disconnected positive lead and the negative terminal of the battery.

The meter is now reading the resistance of any circuit to ground that exists in the boat's wiring. The reading on the Ohm meter display can help you identify the cause of the leak.

0-10 Ohms means it is most likely a piece of equipment left on
10-1k Ohms is a low-drain piece of equipment left on, or a serious ground leak
1k-10k Ohms is a minor leak
10k+ Ohms is an insignificant leak

How Big is The Leak?

The ammeter function of the multi-meter can tell you what the current leakage is. If your meter can read up to 10 Amps DC, then you can use it to measure amperage for leaks down to about 1.3 Ohms resistance on a 12 VDC system, or 2.6 Ohms for a 24 VDC system.

To see how big the leak is, put the probes on the positive battery post and the disconnected cable. The meter readings can be interpreted as shown:

<1mA — insignificant leakage
1–10mA — minor leakage
10mA–1A — major leak or some equipment left on
>1A — Usually some equipment left on.

[capngregg]

When you say your wind generator is "tied off" do you just mean that it can't rotate? Does the wind generator have a circuit interupter? (switch, etc)

Galvanic leaks generally only occur when some sort of electical path is created to the water surrounding the hull. For instance, if a ground path from the engine (which includes the prop and shaft hanging out in the water) is created back to the ships batteries either through a direct ground cable to the batteries or through grounding busses. At the same time if there are components connected on the positive side of that battery such as an inverter it may cause an AC ground path back to the battery

This is a crude example but I have seen it done before. The battery banks should be able to be completely isolated via various selectors. If there is still a leak noted the cleanliness and integrity of the battery cases should be investigated. There is a good article on galvanic isolators in Yachting Monthly on this issue. (www.ybw.com)

Good Luck!

[SanderO]

Shiva has several always on... connected directly to the house battery loads... the Link with the display set to ON always, the XintexS2a propane sensor and solenoid, two auto type stereo memories. I don't recall the min load... but it's pretty small. But without a charging source... it could drain a battery over several months I would think.

[timebandit]

Altenators require about that much to energize.

[EscapadeCaliber40LRC]

To answer some questions, I tied a rope through the wind gen blades to act as a brake and monitored the current flow in the dark of night when the solar panels wouldn't be working. The boat is on a mooring ball with low night time ambient light, stars mainly. There are several direct circuits with fuses. I pulled all the fuses and turned the battery switch to off. Two radios one VHF that is circuit breaker controlled, and a directly wired HF. The back light of the 2000R and its circuitry must consume a few microamps. The stove is propane and its monitoring circuitry has a circuit breaker that is cut off by the main 12DC circuit breaker being off. The bilge pump direct wire is fuse controlled I think, but I pulled that fuse along with several other fuses that I've located. The alternator is normally switched off it does have a red blinking LED light when switched off, but that won't pull 100 milliamps. I can turn the light off by switching the alternator to the "on" position. The mast wiring is definitely suspect as I have a problem with the wind direction indicator as well currently. I need to do the nitty gritty testing that SailingDog so kindly supplied. I thought I found the source the other day when I found a power wire drapped in the bilge, it went to the bilge secondary sensor but after elevating that wire the mysterious current flow remains perhaps reduced a bit. Its at the limit of the monitor's ability to identify. Thanks for all the great suggestions!

[steve301]

You might not have a problem. I have been tormented by a .1 to .2 current drain from my AGM batteries, as shown by my Link 20 monitor for the past year. After checking with 2 well known marine electricians in Annapolis, several certified and well established techs, and Jack Rabbit Marine, the overall concensus was that the Link's default reading was .1 or .2 current draw and that the link monitor itself was the source of the draw. (Check the askjackrabbit.com site for a fuller discussion of this issue.) This current use will not be a problem if you are hooked to shore power or can keep your batteries otherwise charged. During winter layup, I was advised to remove the Link's fuse or to disconnect the batteries positive leads, and charge the batteries about once a month over the winter. Now, I'm not saying that you do not have an unwanted current problem. but just relating my experience. good luck.