Power Leaking and Electrolysis...

[Rick]

Sorry, I missed that main point in my horror at the suggestion that the shaft not get bonded!

[Alan Wheeler]

Yeah I was in shock and horror too. But I don't think that is what Engnate was suggesting. I think he is suggeting it IS kept "floating". Big no no. EngNate, sorry mate, but becuase it is physically isolated, doen not mean it remains electricaly isolated. In fact, physicaly isolating it increases the potential created. The rule is, Two dissimilar metals placed in an electrolyte will produce and electrical current. You have effectively made a battery by doing what you did. How do you stop a battery from working? you short the cells. So you electricaly attach the sfat coupling to protect the shaft and prop. The anode is sacrificed first before the Prop and shaft.

[svHyLyte]

Rick...

I have discovered anoher thread on the SSCA Forum at http://www.ssca.org/sscabb/index.php...=3195&page=0#9
that indicates several others are having a similar problem with indicated amperage discharge on a Link 10 with no apparent loads. If I recall correctly, you were one of the people involved the design of this instrument and I'm wondering if there is any possibility of a systematic error with the unit. If not, is there any possibility that one or more of the diodes in the alternator could be failing and accordingly "leaking" power back to ground (to rely on Alan's hydraulic analogy)?

At this juncture we've got the new prop-shaft and shaft seal from Beneteau, the Drive Saver, the flange plates "faced" and they're about ready to go back into the boat. As it occures, there is inadaquate space in the shaft alley for the extra diameter of the drive saver so the hull-liner/pan has had to be cut away somewhat and then re-sealed (ouch!). In theory, the prop should be back today tho' some mod's had to be made for set-screws to secure the newly machined pins in place so I doubt the $150 estimated cost will hold. N'any case, save for tracking down our amperage "leak" we should be back in the water within a week. (I have no confidence in the boatyard's ability to find that problem and I'm thinking of simply disconnecting the pos lead to the start battery as necessary until I can do so myself.)

Now here's another question. In theory there is a lead from the Echo charger on the Freedom 20 Inverter/Charger to the starting battery to charge that when the house bank reaches full charge. To work, however, it would seem that the starting battery gound would have to be connected to the ground lead from the Inverter/Charger. Further, the house bank and the starter battery are connected via an Isolator so that, in theory, the alternator will charge both when it's actuated. Again, however, wouldn't the house bank and the starter battery have to both be connected to the ground lead from the alternator for this to work? If so in both cases, then the house bank and starter battery must always be sharing a common ground, No?

As an engineer, I sometimes think better graphically and I've been trying to make up rudimentary wiring diagrams to understand how these systems should relate and some things have me stumped. For example, we've two "house" banks of two T-105's in series. The Link 1000 supposedly see's these as one single battery and controls the charging of both from the Inverter/Charger accordingly. However, unless the banks are cross-linked on the pos. side before the switches, it would seem that they could not both be charged unless their switches were both on. If they are cross linked, it would seem that there would need to be an isolator (or combiner) in the cross link or they would both always be "on" whenever either's switches were on, Yes?

Your observations will be appreciated.

s/v HyLyte

[DeepFrz]

Jeff, all of your batteries should share a common ground bus. So should your AC be connected to the common ground bus.

Do yourself a favor and set your house batteries up as one house bank.

Phil.

[Rick]

I agree with Phil yet one must be very careful in making one and only one connection to ac ground and, even then, one should use a galvanic isolator or an isolation transformer.

For sure the inverter/echo charge battery must have a good ground with the start battery for the echo charge to function properly.

I have an intense dislike for diode isolators used in power circuits. They are ultimately not reliable and/or reliably installed and applied. Battery combiners are more reliable (in general) even though they are ostensibly more complicated. One reason for the better reliability is that it is easier to maintain a high current terminal connection connected to a non-heat generating device that when connected to a high heat generating device like a diode isolator operating anywhere near rated current.

The E-Meter is easy to check for "zero". Merely disconnect all "ground" connections from the load side of the shunt (not the battery side). Obviously one does not disconnect any of the meter leads in doing this else the meter will not function properly. The E-meter should "rack" between 00.0 and -00.0 Amps (00.0 implies a positive sign). When perfectly calibrated (not always done at the factory) the average amount of time spent racking negative will equal the average amount of time racking positive and the net result will be a zero accumulation of Amp-hours over long periods of time. Internally the analog circuitry of the meter is stable to better than an equivalent of +/-30 mA.

It is possible for someone able to read and follow directions to re-calibrate the zero in the field yet in doing so one must not inadvertently change the voltage calibration (rarely ever necessary unless the factory failed to do so properly).

[svHyLyte]

I hope!

I have just been advised that the electrical problem on HyLyte appears to have been resolved!

While cleaning up some spilled oil under the engine bed a laborer happened to notice that a power cable had a some melted insulation. He called it to the attention of the yard foreman who checked and found it to be the cable connecting the starting battery to our Panda Generator. Either the cable had been damaged during the generator installation or, more likely, had chafed through where the cable was laying against the bonding strip on the starboard side of the engine bed. (The bonding strip is a thin strip of copper that looks like a ladder--two continuous strips with cross bars at about 2" intervals--that runs the length of the boat. The edges are fairly sharp, as I can attest, having given myself a good slash when I scraped my arm across it a few years ago.) The yard foreman indicated that some of the insulation had melted off around the damaged portion of the cable and that the resulting exposed copper wire could easily make intermittent contact with the bonding strip. Further, even a little water in the engine gallery would have been a path for power leakage between the battery cable and the bonding strip--hence our mysterious starting battery drain--and, probably, the electrolysis of the prop, shaft, strut et al. The yard is in the process of replacing the cable as I type (the new cable will be passed through a length of reinforced plastic water hose where it passes through the engine space) and I hope to be able to get the boat reassembled and back in the water within the next few daze--so I can do all of the other checks you've all suggested--just to be on the safe side!


N'any case, thanks for everyone's help. I shall add a final post to this thread (I hope) to advise everyone of the in the water tests!

Cheers,

s/v HyLyte

[DeepFrz]

Congratulations, well done

Phil

[EngNate]

http://www.abycinc.org/calendar/even...fm?eventID=152

[svHyLyte]

Toil and Trouble...

As a follow-up on this thread, earlier today I received good news and bad news.

The good news was that the electrical cable to our generator has been replaced, a new starter battery installed, the new propeller shaft is in-place with the DriveSaver installed and a new Cutlass Bearing. Our remachined Prop (with new pins) arrived yesterday and should be installed today and, in general, the yacht should be ready to be relaunched on Friday.

The bad news is that after having technicians theoretically chase down and "prove" all of the wiring connected to the starting battery circuits, and then reconnect everything, the Flaming Link 10 still indicates a power drain of .6 amps!

Now--our boatyard has hired "Expert Electrician 2.0" who claims to have put a very costly, "accurate", metering device on the system and found only a .035 amp (35 milliamp) drain, which would correspond to the power required to illuminate the Link's display. With this he concludes that we're seeing a calibration error in the instrument rather than a drain.

My question then is, How likely is this? Does anyone have any experience with calibration errors?

In any case, we've sent a request to Xantex for the instructions to re-calibrate the instrument. Once rec'd, I will post them if anyone is interested.

Regards,

s/v HyLyte

[EngNate]

At the risk of imflaming Rick and others again, I suggest this:

With a 6-32 nut in hand, disconnect the shunt sense leads from the shunt (note not to reverse them when re-connecting). Use the nut and one of the screws to connect the wires together. Observe the amp reading. If it is zero, there is current going through the shunt and the Link is showing it. If not zero, disconnect the leads at the meter, again noting which is which. Connect a short jumper wire between the two meter terminals, and note the Amp reading. If not zero, the Link is faulty, re-connect the leads to the shunt. If zero, the wiring between the meter and shunt is picking up stray electromagnetic noise - the wiring is faulty, repair or replace it, observing the installation instructions fully. That should get you to the next step.

Fortunately or unfortunately, I won't be online again for a number of days.

Nate

[Sandero]

I have observed the same "drain" on a link20... 1 - 2 AH per day o each bank. But I also have a Link which crashes every 2 weeks or so for no reason. The display freezes and you can get the buttons to do anything. To reset I remove the main Link fuse and it erases the values.. zeros out and starts again. Did a reset after a crash this afternoon. Note... the vessel is in winter lay up on a TruCharge20 and there are NO loads on Start Bank and minor loads on house bank.

I suspect the Link is defective. A crashing monitor is defective in my book. I don't know if the AH consumed is related.. but when I get JR Energy to replace the head.. I will find out.

They are also making a "service" call to the boat to check out the entire installation. I assume they can determine the reason for the disappearing AHs...

Stand by till early May when they show for this service call.

Jef
sv Shiva
Contest 36s

[EngNate]

8-32 nut, sorry

...when looking at AH, make sure you're seeing a (-) sign, otherwise the value is normally meaningless. I've observed glitches locking up Link's on occasion, requiring a power-down reset, but it should not happen repeatedly, or something is wrong...

[svHyLyte]

continues...

I have just been informed that Expert Electrician 2.0 has discovered that Expert Electrician 1.0 did not use the twisted wire harnesses that came with either the Link 10/E-Meter or the Link 1000 when he installed them. Instead he apparently used heavy Ga. wire that was so stiff it couldn't be properly twisted, and so large it couldn't be properly connected to the lugs on the backs of the meters. Why the twisted wire harnesses that were supplied with the meters were not used remains a mystery but, when the correct wiring was substituted, "Viola", meter readings reportedly match Expert Electrician 2.0's independent meter readings--i.e. about 35 mA drains (on each) with no loads save the meter's themselves.

I should be angry I suppose but had it not been for the errant meter readings, I would very likely have put off our haul-out for anther year by which time our prop and shaft strut would likely have been destroyed as was our prop-shaft. So--as my darling wife says--we were lucky, if one can call a $7,000+/- haul-out lucky! Better this than loosing the prop, shaft and who knows what-all in the northwest channel into Key West or on the Miserable Mile in Sanibel when we're fighting bad winds and/or tides! (My wife, the eternal optimist, can always see the up-side in the down-side!).

N'any case we're being re-launched at 0830 EDST tomorrow. Hopefully all will be well! We shall keep you informed with what I sincerely hope will be last our last post/follow up on this thread!

s/v HyLyte

[CaptainK]

Good luck with your boat, HyLyte.

Electricity problems can be a pain in the a**!!

[DeepFrz]

HyLyte,
In keeping with the sunny side up theme set by your Admiral, it's a very good thing that the partially shorting cable was found before things heated up.

Course I didn't have to spend $7000.! Vicarious living does have it's rewards. ; }