Engine stalls when raising or lowering anchor
- Thread starter Building a boat
- Start date
This gave me an idea. With the engine running turn the key off but do not kill the engine. Try the anchor windlass, does it kill the engine at idle? I suspect that the heavy load on the alternator is causing the issue, but I do not know why the governor doesn't catch it. Maybe the governor mechanism is worn out.
Gave you an idea? That's exactly what I have been saying!
The power output of a diesel is in proportion to its speed. I imagine if the OP rev'd it up high it wouldn't stall. I suspect the alternator is loading it to the point where the governor is "out of regulation," meaning it's putting as much fuel in as it can at that engine speed, and still isn't making enough power to maintain RPM. That said, if he revs it up and does this he risks burning out the alternator.
You are correct, I hadn't read the entire thread.Gave you an idea? That's exactly what I have been saying!
I hadn't given any thought to overheating the alternator, good point.
He did say that if the idle was set any higher that it made slow maneuvering difficult. Sounds like the idle is set high enough but the governor isn't able to deal with the additional load, and it should be able to in my opinion.
Difficult cases like this are often caused my multiple failures. Could be a combination of several things.
Examples: dirty injectors, bad battery bank, tight bearing in the windlass, plugged exhaust, worn governor, large alternator on a small engine.
Well, the only two messages the OP, @Building a boat , has ever posted are the two in this thread. I certainly hope he comes back and tells us what happened!
If you're reading, OP, I wonder if you can tell us more about the circuit that the measurements above come from, and if you can re-run the test measuring the current that the alternator is supplying?
Thanks,
jv
Sorry , traveling at this for a week , lousy internet connection.
Lets see if I can answer most questions
Brand new house bank - 2 6v trojans
Setting idle higher doesn't help till you start to get to point it may be bad for changing gears
With engine off, just by batteries anchor comes come smooth
Governor just replace, all springs, waited 2 months for ;0)
Mechanic feels there are no engine issues
1). No smoking
2) Engine starts up right away with no hesitation
3) Run engine at full revs - no over heating
Measurements all come from Xyntrex smart meter
Orginal 55Amp alternator
Replaced fuel filters twice
There are some odd wiring issues that I was able to identify before I left. I would like to get a better look at it and do a wiring diagram when I get back. If you can wait till I get back at it. April 15th would be great
Thanks Ryan
Lets see if I can answer most questions
Brand new house bank - 2 6v trojans
Setting idle higher doesn't help till you start to get to point it may be bad for changing gears
With engine off, just by batteries anchor comes come smooth
Governor just replace, all springs, waited 2 months for ;0)
Mechanic feels there are no engine issues
1). No smoking
2) Engine starts up right away with no hesitation
3) Run engine at full revs - no over heating
Measurements all come from Xyntrex smart meter
Orginal 55Amp alternator
Replaced fuel filters twice
There are some odd wiring issues that I was able to identify before I left. I would like to get a better look at it and do a wiring diagram when I get back. If you can wait till I get back at it. April 15th would be great
Thanks Ryan
Have you had a chance to deeply discharge the batteries to see if the engine has any trouble idling as it charges them back up? If the electrical load from the windlass is enough to bog the engine down then I would expect you will have the same problem when the batteries are at a low SOC and can really absorb current.
That does not match my observations. When my batteries are deeply discharged (50 - 60 % SOC) my 80A alternator can’t reach 14.4V for some time, even at 2800 engine RPM’s. It doesn’t just push out ever increasing current to saturate the batteries. It’s probably not good for the alternator to do that for extended periods of time (as Maine Sail’s Lithium write-ups document), but for the time it takes to run a windlass I wouldn’t worry.
I believe you are misinterpreting what I've said. The load presented to the alternator is what determines how much current it puts out, according to the regulator and the amount of field current before field magnetic saturation. Just because your batteries are low doesn't mean the alternator will put out ever-increasing amounts of current.
You don't say what kind of regulator you have. If it's a so-called smart regulator, until the batteries get to the set acceptance voltage, often 14.4V, the smart regulator will charge at fixed current - this is called the bulk stage. After this, in accpetance, the regulator will maintain a fixed voltage, and the current will gradually diminish until the acceptance stage is terminated, either by a timer or an acceptance-end current setting, often 2% of the bank capacity. After this it will float the bank at about 13.6V.
The fault condition I was alluding to is when the load connected to the alternator is suddenly much higher - actually, much lower resistance - which can overload the regulator, i.e.., drawing more current than normal.
I would. If the windlass is stalling the engine at idle, and it didn't before, something is wrong. Repeated stressing of the alternator in that way will damage it over time. Also, the thing that's probably loading it so heavily is not right.
My alternator is a "dumb" Hitachi internally regulated model that will "try" to reach 14.4. What I've observed is that it can't put out enough current when the batteries are deeply discharged to reach that level, so it puts out what it can (presumably somewhere short of 80A depending on temperature). As the batteries come up in state of charge (and with it, resistance) the alternator reaches 14.4 V and levels off there, charging in Constant-Voltage mode. I just added a Smart Shunt this winter so I'll report back later in the season with what the alternator actually puts out when it's below 14.4 V.
The windlass is connected to the battery, so from the perspective of the alternator the windlass load is no different than a very low resistance / low SOC battery.
I think we've been through the alternator limitation debate in the LiFePO4 thread and agreed to disagree there. I do agree with you that if this OP's engine is dying from the windlass something is not right and needs to be looked at more.
House bank is 210 AH AGM (2x Group 31 AGMs). There's another Group 27 AGM Thruster battery and Group 24 AGM start battery, but those are probably not very deeply discharged and so not responsible for consuming more than a couple amps.
Thanks. That's probably not enough battery to overload a Hitachi 80A alternator, even when close to flat. I think if you added more, like paralleling more batteries and bringing it to 420 or 630AH, you could burn out that alternator. I am not sure exactly how that alternator would react, but I think that if there's enough field winding before saturation and enough field current from the regulator, you could overload the alternator and burn it out. Alternators burn out. How does that happen? I mean, if you crowbar the output, as they say, will it survive?
(With apologies to the OP for the tangent...)
I think it might saturate the alternator, although I'm definitely curious to see what the Smart Shunt shows. Maine Sail has done some testing of AGM charging at How Fast Can an AGM Battery be Charged? - Marine How To. In those tests he shows charge times for AGM's at 0.4C. 0.4C on my bank would be 84 amps, plus a couple amps into the other banks, and 5-10 amps for instruments and fridge, so definitely over my alternator capacity. Maine also says AGM's can take more; I think the 0.4C in his test was just an example of typical conditions.
I think (though I'm still learning more about this) that the difference is that Lithium (and your crow-bar example) have even less resistance than a low SOC battery, so the alternator is even more "shorted" than the intermediate case of a low SOC battery that presents enough resistance to drag the alternator output down into the mid-13's at maximum field.
Having said all that, and back to the OP - I guess you've got me thinking the windlass will look more like a crowbar, so maybe there's something to your point about keeping an eye on the alternator in this case.
One thing to keep in mind with a windlass is the in-rush current which can be many times its rated draw. When this high load suddenly comes onto the DC system, it pulls the voltage down and the alternator responds by going from low output to max output. This sudden change on a low power engine at idle could be happening too fast for the mechanical governor to respond quickly enough to keep the engine from dying. Think if it like an electrical version of popping the clutch.
Back from vacation and spent a day chasing wiring.
Alternator connects directly to House bank battery.
Starter battery is charge via a Xantrex echo charger which has a max 15amp output
Windlass connects directly to the House bank as well.
I disconnected the windlass from the House and connected to starter battery
Works perfect, motor doesn't hesitate. Appears that the load on the alternator was stalling my engine.
Which opens up a whole bunch more questions, is it the fault of the engine, or the alternator ?
Boats ugh! ;0)
Alternator connects directly to House bank battery.
Starter battery is charge via a Xantrex echo charger which has a max 15amp output
Windlass connects directly to the House bank as well.
I disconnected the windlass from the House and connected to starter battery
Works perfect, motor doesn't hesitate. Appears that the load on the alternator was stalling my engine.
Which opens up a whole bunch more questions, is it the fault of the engine, or the alternator ?
Boats ugh! ;0)
Where can I claim my prize?
( He asked, in all modesty.)That was a good idea, to move the windlass to the start battery as a debug method; it might even work to just leave it there. But, I think your windlass is drawing too much current. I would check it, or have it checked - for binding bearings, worn brushes, shorted armature windings, etc. A good automotive starter and alternator rebuild shop will do this easily, that is, if you can find one anymore.
Cheers,
jv
My 2gm also has trouble handling a large load at low rpms,. The 100amp balmar alternator wiil pull about 70amps from my lifepo batteries at start up. The engine struggles until i bump it up to about 1200 rpm.
Assuming your problem is too little horsepower at idle for the high alternator load, l would suggest driving the boat forward then shifting to neutral and running the windlass with more engine rpm.
Assuming your problem is too little horsepower at idle for the high alternator load, l would suggest driving the boat forward then shifting to neutral and running the windlass with more engine rpm.
