Q: mechanical diesel engine governor controller?

vas

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hi all,

yanmar 2GM20F from the MASE generator is finally with the mechanic who's going to do the full rebuilt.
I've discussed in a previous thread that the main problem with this little motor is that governor is bolted up to 3K rpm contantly so engine starts, runs and stops from 3K which is not kind for any type of engine... Engine at 1K hours suffers from low compression ie stuck rings, bores, valves, seats, etc are almost perfect.

I've drafted a system I'm planing to use with a electromagnet from a large oldschool car engine starter (think a Toyota) which I want to activate when I start up the yanmar so that it pulls the governor down to idle. A few mins later, I cut the 12V to the el.magnet and a suitable spring pushes the governor to an opposite facing stop at 3K rpm. The same when I want to turn off the generator with the output cut off, and revs dropping to idle for a few mins before turning off the engine.
I can do all that using an arduino a relay board and a bit of signaling from the touchscreen I have to run the engine, np.

However, and here's the Q bit, the mechanic mentioned that there's such a device ready made and used in older Fisher Panda generators with a long screw or something somehow winding up the revs and unwinding on switch off. Haven't seen the thing, he just tried to describe it.
Couldn't find something like that on ebay but I did come across various systems that do so in I guess el. governed engines:
https://www.ebay.co.uk/itm/EG3002-U...m=112980615933&_trksid=p2060778.c100290.m3507

Any idea if there's something like that el.mechanical?
Actually I'm going to do mine anyway, I'm interested in finding a simpler solution for my two mates who also have 2/3cyl 4-10kva generators again running at 3K rpm.

cheers

V.
 

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You need to be careful with the main ac alternator.

Currently your ac alternator will used residual magnetism to self excite it’s self, this then powers your AVR (automatic voltage regulator) this will then output dc power to the field to achieve 230v. All of this is happening as the engine runs up to 3000rpm. If you slow the engine down temporarily you will force the AVR to work very hard to try and make 230v when only running at 1000rpm. I suspect you will shorten the ARV’s serviceable life by doing this.
 

vas

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You need to be careful with the main ac alternator.

Currently your ac alternator will used residual magnetism to self excite it’s self, this then powers your AVR (automatic voltage regulator) this will then output dc power to the field to achieve 230v. All of this is happening as the engine runs up to 3000rpm. If you slow the engine down temporarily you will force the AVR to work very hard to try and make 230v when only running at 1000rpm. I suspect you will shorten the ARV’s serviceable life by doing this.

thanks Anthony,

I'll try and study that a bit, but was simply planning to cut gen output whilst doing that cooling idling periods by using an over/under voltage protector that simply cuts output when not within a range.
Wonder if that's enough of a protection or if I should be "cutting" the power to the AVR somehow instead. Back in the drawing board then!

BTW, re the other question I had, there was a grille on the side of the generator by the engine and I could stick my hand with a 13mm spanner and undo the 8 bolts and disconnect the yanmar without having to take apart the generator!

cheers

V.
 

vas

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You could fit relay in between the main alternator and the AVR power supply to stop excititaion during the 1000rpm operation. Which model AVR do you have fitted?

give me a few days, it's freezing cold now... I've not actually moved the generator, it's still on the MASE frame in a v. awkward place with lousy access. I'll move it to a more accessible spot on Tue or Wed and try and see what I've got in there. I know it's a Mecc Alte MR2-160 (don't think its the 200)
http://www.powertechengines.com/MeccAlteData/MR2.pdf

With regards to the solenoid I would used something like this-
https://rover.ebay.com/rover/0/0/0?mpre=https://www.ebay.co.uk/ulk/itm/322371707845

Good news about not having to strip the whole alternator.

thanks for the pointer, bought already a v.cheap one with shortish travel, not sure it will be enough, if not I'll get one of these.

cheers

V.
 

vas

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There is nothing wrong with running diesels at a constant rpm for long periods. In fact they love it.

Perkins 4.107s and 4108s used on reefer containers often ran for 20,000 hours and some 30,000 hours plus before needing a rebuild.

do these babies work at 85% of WOT THROUGHOUT their life, and START from stone cold and STOP from boiling hot from these revs?
if they do, then probably my small yanmar is not fit for purpose, shall I claim my money back from MASE?

btw, it's not worn out, just got stuck rings
 

kashurst

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are you trying to solve the wrong problem?
the engine isn't worn out, it has stuck piston rings after 1000 hours. If the rest of the engine was showing excessive wear or damage I would agree with you. As it all seems more or less perfect, I think the engine is quite happy bursting into life. If there were any oil pressure or temp related side effects they should be obvious by now. Assuming you start the gennie with no or little electrical load, there is very little load on the motor when it starts. Regarding shutting down, the manuals for my current and previous gennies have usually stated remove the electrical load for a few minutes before stopping.
Is the cause of the stuck rings more likely to be poor maintenance in previous ownership? Insufficient oil changes/wrong oil/allowed to overheat?
 
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vas

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are you trying to solve the wrong problem?
the engine isn't worn out, it has stuck piston rings after 1000 hours.
Is the cause of the stuck rings poor maintenance in previous ownership? Insufficient oil changes/wrong oil/allowed to overheat?

tbh I'm not sure...
The only info I have is locally from 4-5 3K rpm generators all closing or over 20yrs and all having problems (burning oil, difficult starting, over/under heating, noisy...) and they are not high hours! On top of that a couple of mechanics that I can trust claim that they only see issues on the high stressed 3K generators and not on the 1.5K ones. Hence linking the two.
OTOH, following the rebuilt I'll probably be putting from 10 to 100h a year on it. 10 just for watermaking, a couple of evenings/nights in a marina with a bad swell stabs, a few hours aircon, that sort of thing. So I may ignore and do nothing, but since it's going to cost a tenner (which I already paid anyway :rolleyes: ) I may as well try it, not much to loose.

V.
 

vas

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closing threads...

well, 4months and 200euro later I'm the happy owner of the following:

https://www.ebay.co.uk/itm/Solid-St...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

https://www.ebay.co.uk/itm/65V-260V...e=STRK:MEBIDX:IT&_trksid=p2057872.m2749.l2649

and most importantly

https://www.actuonix.com/P16-P-Linear-Actuator-p/p16-p.htm (chose the 50mm travel, 256:1 ratio as I measured close to 90N force to open the governor to WOT)


Haven't had the time to put all that together yet, but have got a mock on a breadboard running the actuator fine the rest of the things are already running on the two main engines, so not worried.

Linear actuator will be driven by an arduino board (either teensy 3.5 or ESP32S), start at 1k rpm (give or take) check coolant temp (if it's already hot) or with a timer (if it's cold) up the rpm to 3K (feedback sensor close loop working here) at which time the Over under voltage relay will pass a signal to the Solid State relay and trigger power output.
FWIW (well more than 50euro) if I'd do it again, I'd get a simple linear actuator without feedback and stop the movement when the signal from the over-under would change from on to off (or vice versa as it has a control output as well as the main signal) Then I'd have to use a timer to move down rpm before turning off, but it would be ok.

When generator is instructed to turn off, linear actuator will drop rpm to approx 1k rpm, stay there for a timed period of say 2mins and then the linear actuator will go out as far as it can and kill diesel supply to the engine stopping it. BTW, factory idle screw is undone all the way so that governor actually closes diesel hence no need to fool around with the stop lever under it (except for emergencies where I can go down there and just push it to turn off the motor). Note I don't programmatically alter with 230V output, it will be auto on and off as and when rpm is right and the thing produces what it should...

When restarting the engine at a later point, linear actuator will come again up to 1k rpm point before cranking. Probably would make sense to return the actuator to the 1k rpm point at the end of the power off cycle. I'll see.

Doing this means I also removed the main liability of the MASE setup - the needle fuel stop solenoid which was on the entry to the high pressure pump and was not always working as it should...
If someone wants an occasionally working stop solenoid give me a shout :D

Finally all that means that I'll scrap the already water damaged and lousy repaired control box of the yanmar which did oil/temp switch testing, and had two relays to engage starter and stop solenoid.
This damaged control box killed the original MASE dash panel, if someone wants any bits out of it (like the hour counter or something) let me know. It's a v.poor designed thing with dodgy microswitches secured in place with tiny metal strips.

Starting/stopping and general monitoring will be done with custom NMEA2000 sentences from a touch screen on the lower helm to the arduino on the generator. Normal engine NMEA2K sentences will be used with engine id #2 (#0 is port main engine, #1 is stbrd) so that I can monitor and have warnings on the two Garmin plotters and all other displays onboard.

cheers

V.

PS. forgot to mention that yanmar 2GM is back in place after the full rebuilt and works fine (unless you've forgotten that you undid the idle screw and try to start it for 5 mins :rolleyes: )
 
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volvopaul

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hi all,

yanmar 2GM20F from the MASE generator is finally with the mechanic who's going to do the full rebuilt.
I've discussed in a previous thread that the main problem with this little motor is that governor is bolted up to 3K rpm contantly so engine starts, runs and stops from 3K which is not kind for any type of engine... Engine at 1K hours suffers from low compression ie stuck rings, bores, valves, seats, etc are almost perfect.

I've drafted a system I'm planing to use with a electromagnet from a large oldschool car engine starter (think a Toyota) which I want to activate when I start up the yanmar so that it pulls the governor down to idle. A few mins later, I cut the 12V to the el.magnet and a suitable spring pushes the governor to an opposite facing stop at 3K rpm. The same when I want to turn off the generator with the output cut off, and revs dropping to idle for a few mins before turning off the engine.
I can do all that using an arduino a relay board and a bit of signaling from the touchscreen I have to run the engine, np.

However, and here's the Q bit, the mechanic mentioned that there's such a device ready made and used in older Fisher Panda generators with a long screw or something somehow winding up the revs and unwinding on switch off. Haven't seen the thing, he just tried to describe it.
Couldn't find something like that on ebay but I did come across various systems that do so in I guess el. governed engines:
https://www.ebay.co.uk/itm/EG3002-U...m=112980615933&_trksid=p2060778.c100290.m3507

Any idea if there's something like that el.mechanical?
Actually I'm going to do mine anyway, I'm interested in finding a simpler solution for my two mates who also have 2/3cyl 4-10kva generators again running at 3K rpm.

cheers

V.

What you are asking is exactly what I have in my workshop in a FP genset .

If you need a photo send me your email.
 
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