Please help with my genset problem . . .

[nhschneider]

My family and I are getting ready to leave Darwin for Indonesia and we're having a problem with our Aqua Marine My-T-Gen, which is a 150-amp alternator mounted to a Kubota 6-horsepower EA-330-E single-cylinder diesel. The unit has only had minor problems in the 1,100 hours since we installed it. We have an old HD Power Solutions regulator controlling the alternator.

The problem is that the engine will start to 'lug' down to such a low speed that the amps will start to drop because the alternator is turning too slowly. At first I thought it was the alternator bearings so I had those replaced and the rotor turns easily now even though it did before as well.

Dan, the owner of Aqua Marine, thinks the regulator is demanding too much from alternator. But if the alternator can only produce 150 amps and has done so for 1,100 hours without lugging the engine down, how can the regulator make the alternator produce so much power that the engine can't keep up? I'm trying to secure a replacement regulator but I'm skeptical that it will solve the problem.

The engine uses electric raw water and coolant pumps so there is no other load on the engine. The fuel filters are spotless - besides, the engine runs fine when the alternator is turned off. Having lived closely with the engine for almost 4 years now, I'm pretty sensitive to the way it sounds under different levels of load. What is happening now is definitely a very high load.

Any ideas would be greatly appreciated.

Fair winds and calm seas.

[Oceanride007]

Hi
Genset problem, if a diesel engine is being slowed down by the load, symptoms include overheating, exhaust smoke will get darker even black. You haven't mention this, so I bet your having problem with the governor. As far as I know all diesels have a governor, the fuel lever pushes against the governor counter weights and centrifugal force of the weights will drive the fuel pump rack. On most engines the governor has a lot of speed droop, Generators must run at the rated speed to give you the cycles, these need far better regulation, isochronous maybe.
Running such a engine could be very damaging to AC Motors. You'll have to test it with other kinds of load, traditionally immersion elements/resistors are used.
I just expained a traditional mechanical governor, now electronic versions are being used, but I imagine they will still push the fuel rack. Look up your service manual, its possible the fuel rack is stuck, maybe in the fuel pump block. Do the checks here as suggested but if your in a hurry take it to a fuel pump tech in Darwin.

Oceanrider, boatless but also part time Marine Engineer.

[noelex 77]

We have a similar DC generator, but hardly use it with solar these days.

The throttle setting does need to matched to the load. If the batteries are very flat and demanding a lot of current it will lug at low throttle settings. Ours is 14hp 2 cyl engine, so it will be more critical with your small engine.

Usually the throttle control on these set ups is a simple friction nut and my guess is that this has slipped and the throttle setting is lower. Often the difference of a few 100 rpm is enough to make a big change.
It could be that the engine is down in power for another, more serious reason, but this is the first thing to check.

One of the beauties of a DC generator is that they can be run at different speeds and an adjustable throttle (I used a SS turnbuckle) is worthwhile. After the initial high output of the alternator the battery acceptance will drop off and the throttle setting can be reduced, cutting down the noise etc.

The other possibility is the regulator. Some have a soft start feature and if this has failed the engine might struggle initially. Mine has a regulator without a soft start and manages perfectly anyway, but it is a larger engine.

[nhschneider]

Thanks for the replies. I think Oceanride might be on to something, however, the comments about running the engine at specific speeds are irrelevant as the genset only has a 12vdc alternator on it - it doesn't produce any AC current at all. Regardless, I am now very suspicious of the internal throttle linkage or the governor. Since this is a single-cylinder engine, the injector pump is buried in the engine as is the governor. Its going to be a very invasive procedure to remove and inspect it. Furthermore, once its apart, I'm not sure I'll be able to identify a problem. With no dealer for the engine for thousands of miles, finding repair parts is going to be a challenge.

Just the same, I appreciate any input.

Fair winds and calm seas.

[colemj]

Originally Posted by nhschneider

With no dealer for the engine for thousands of miles, finding repair parts is going to be a challenge.

Maybe not, those Kubota engines are used in a lot of small garden and industrial machines. If it is a non-marine part like an injector or injection pump, you may have good luck finding them in tractor stores and industrial machine places.

Mark

[DeepFrz]

You didn't say how many amps the alternator is putting out when the engine gets dragged down. That is certainly one of the key items in the equation. Do you know what the output is? If you are demanding more power output the alternator will try to supply this. It will reduce the life of the alternator though.

Some other things to check:
Make sure the exhaust system is not plugged up, especially at the exhaust injection riser where the coolant water is injected into the exhaust system. At 4 yrs. this is certainly a maintenance item (past due if not previously performed).

Is there an intake air filter? If so make sure it is clean.

Is the generator in an enclosure? Make sure the engine is getting enough air.

Make sure you are getting enough fuel to the engine. Proper maintenance and inspection of the fuel system may show up problems you haven't thought of.

[Oceanride007]

Deepfrz is right in that your got to do the basics first, I didn't know about this kind of gen set that drives a DC generator, hence my earlier remark about cycles is relevant to AC only.
I think it unlikely that the Fuel Pump is inside the crankcase, due to likely hood of Diesel contamination, still I could be surprised, hence when you do get this solved, please give a summation.
Darwin is remote, I bet there are many home generators in NT of various kinds, labor rate will be extreme I bet. You won't get this solved in Indonesia. Singapore and Phuket are the next most likely.

Really if this is not a simple fix, and this equipment is crucial so that you don't become a casulty/avoid anymore time wasting in Darwin, I think you better think of a portable generator at least make sure that your Windgeny/solar/oversized Balmar/belts are up to it. Then sell the portable generator when its no longer required.


Oceanrider

[nhschneider]

Originally Posted by DeepFrz

You didn't say how many amps the alternator is putting out when the engine gets dragged down. That is certainly one of the key items in the equation. Do you know what the output is? When the engine lugs down, the output of the alternator drops to less than 30 amps. I assume this is because the engine is turning too slowly. If you are demanding more power output the alternator will try to supply this. It will reduce the life of the alternator though.

Some other things to check:
Make sure the exhaust system is not plugged up, especially at the exhaust injection riser where the coolant water is injected into the exhaust system. At 4 yrs. this is certainly a maintenance item (past due if not previously performed).

Is there an intake air filter? If so make sure it is clean. Air filter is clean.

Is the generator in an enclosure? Make sure the engine is getting enough air. No enclosure.

Make sure you are getting enough fuel to the engine. Proper maintenance and inspection of the fuel system may show up problems you haven't thought of. Beside the puny filter on the engine, I have a Racor with a 2 micron filter upstream and it still looks brand new. The sight bowl is spotless as well.

Thanks for the suggestions. As a test this morning, I started the genset, disconnected the regulator, put the throttle to the Wide Open position and ran a jumper wire from 12 volts positive to the field terminal on the alternator. The engine immediately lugged down again to where it was just barely running and only putting out a fraction of the amps that it usually does. From my limited knowledge, this would suggest that there's something wrong with the governor. Would you agree or disagree?

Thanks for your help. We have almost 3,000 miles to go before we get to Thailand and running our propulsion engine to charge our batteries will use almost three times as much fuel.

[Oceanride007]

So full load is 150 Amps, but at barely running less than 30 Amps. But you won't tell me if the exhaust is black or whats happening with the rack/control rod/output from governor. It really is crucial information.

Can you get reduce the load, if so what is the maximum load (Amps) you can have at working RPM.

What have you got connected on load side, maybe something is sinking the load and your over current protection is not working.

Connecting 12 Volts to field winding, seems a bit rash when we haven't decided where the problem is, think your playing Russian Roulette there. But if this is a car type alternator that has a rectifier circuit and you have a problem with it take it to Auto technician.

Oceanrider

[RaymondR]

Hi nhschneider, I am over on the little blue sloop Roughnecks Revenge anchored off the DSC and am fairly familiar with both diesel engines and alternators. I might be able to help, drop by and we can have a yarn about the problem.

[Boracay]

HD Power Solutions has a website with trouble shooting guides for several of their regulators. There are basic and advanced sections.

It may be worthwhile downloading their guides and having a read.

It may be also be worthwhile to identify your regulator model and to contact
HD Power Solutionsfor advice.

[Oceanride007]

Hi theres a new thread with a similar problem, think its sticking fuel pump. Could you comment here and tell us how this was resolved. It may help
Thanks

[sailinglegend]

We have the same Kubota engine on our Fischer Panda DC genset.

I would suggest it is some kind of fuel problem, not the alternator load. The load is demanding more fuel which just isn't being supplied.

We put on new filters and had similar problems - discovered there was a pin-hole leak in the new filter letting in air. Check the return diesel in a jar and let the diesel bubble up to make sure no air is getting through.

The fuel pump can easily be removed by loosening the screws equally, but get the cam in the right position to take off the load completely, and get the injector checked too.

The other problem we have had is water ingress due to a badly positioned waterlock. Twice the exhaust value has rusted. A compression test will show any problems - should be 484 PSI. I bought a diesel compression tester for £50 on ebay.

Download the manual here:
http://www.sv-zanshin.com/manuals/fi...shopmanual.pdf