Success! Youtube vid showing whole system

[mbryner]

Good results w/ taking output from ST head through toroid isolation transformers, then bridge rectifier, then large choke, then MX80 charge controller.   Charging at 1600 watts.   Sorry if you're all sick of this subject, but this is just to post results.

In the video you can see in order of appearance:
1. happily spinning push rods
2. thermometer measuring 180 F, but engine had been shut down for a few mins and it wasn't up to temp again
3. propane tank muffler, fuel filters x 2 for diesel and future waste oil
4. new drain valve for coolant (makes it easier to work on)
5. drain pipe for oil exchanges (ball valve is hidden below engine and protected from bumps)
6. sight glass for oil level, currently taped to frame but will go back into oil fill hole above camshaft to give true "running" readings
7. Selector valve for switching between regular diesel and waste fuels
8. breaker boxes, toroids, bridge rectifier (you notice 2 bridge's but one is just on the heat sink as a spare)
9. plywood battery box is under everything else, sealed and vented w/ 2" PVC to outside
10. Outback power panel w/ DC breakers on right, AC breakers on left, 3600 watt inverters x 2 inbetween
11. MX80 charge controller showing charging at 1600 watts
12. Trimetric showing charging at ~21 Amps (multiply by approx 70 for true watts), batteries at 54 volts, 60% charged.  It's been raining and I can't expect the house contractor to watch the batteries.
13. Sound of the propane tank muffler from outside.

I think the toroids add a noticable bit of inefficiency, because previously the 'roid loaded down at 1600 watts, but seemed to cruise happily.  Now it seems to be loaded fairly heavily.  It was dark so I couldn't look at the exhaust.   The toroids get pretty warm (can't hold your hand on them for more than a few seconds).  They're rated for 1200 watts each.   I probably shouldn't put 1600-1800 watts in series, but from what I've heard toroids should be able to handle being a little overloaded.   If I find a decent price 5kw 240/120 transformer at surplus, I'll probably swap it for the toroids.

Thank you all,
Marcus

[mobile_bob]

Marcus:

very nice to see the old girl making noise again!

i am a bit puzzle with the toroid issues, i suppose it might be that they don't do well
at lower than 60hz?  you are running at lower rpm right?  maybe you are powering them with
~42hz or so?

otherwise it looks like you got your power back up and that is the important part, the rest is just details
to work through.

bob g

[mbryner]

Thanks Bob.  Yes, about 450 rpm.  Good point about the toroids: 450 rpm is about 42 hz.  Maybe that's why they are getting warm.  I'll research that more.   

I forgot to mention, I think I'll turn the dipper more flat instead of knife edge at this low rpm.  (Wasn't that your suggestion once?)  If it starts slobbering, it can be turned back, but it can't hurt to have more lube to the big end, right?

Marcus

[mobile_bob]

if your using the stock top end hole oiling system, then yes, i would suggest doing whatever you can
to get all the oil you can up there.

it might be that at 450rpm, turning it flat won't cause it to slobber but ought to assure more oil is available to the big
end feed holes,,, seems reasonable to me.

you are quite the inspiration to those of us not quite able to get on with our projects, lessons learned vicariously are much less
costly than those learned first hand.

the way i see it, while we all learn from other successes, it might be we learn more from others failures (if we can call them that)

better way to put it might be "the failures of others equipment through no fault of their own"



bob g

[mobile_bob]

here is a link, that might provide some light as to why the toroids are running warmer than you like

http://www.toroid.com/custom_transformers/technical_bulletin_2.htm

i haven't time to fully read it, but there seems to be some verbiage relating to derating for reduction of frequency?

this might or might not apply to your setup

bob g

[mobile_bob]

something else comes to mind too, that being power factor that the transformer/rectifier load presents to the generator
a poor power factor (which is likely and usual for trans/rectifers) use up capability of the generator that would otherwise be available
if the power factor was near unity, and

harmonic distortion of the generators output, if the distortion is much over perhaps 5% (which is likely) that distortion results in
added heating in the transformers.

might be it is the sum total of a variety of factors that all are working to reduce the overall efficiency of the system, and cause the transformers cores to run warmer than you like.

bob g

[bschwartz]

GREAT !!!!!!  Not tired of this at all.
Thanks for posting this.  We seem to share quite a few common parts.  In you vid, I see the same injection line heater, Outback charge controller, Outback inverter, same fuel selector switch etc.  Yours is all just cleaner than mine 

The one thing I didn't see was the choke you are using.  How big is it?

[mbryner]

Thanks Brett.  Oh, the choke, ha, I forgot to include that in the video.  It's in a plywood box under the inverters, not visible in video.   It weighs probably about 100 lbs.  At least that's what it feels like!  Just an old transformer that the off-grid installer had lying around.

Bob, according to that link:

Do not specify a lower rated frequency than needed. (A 60Hz transformer has 20% higher rated power than a 50Hz transformer of the same size and weight.)

That would imply that you have to derate the transformer as frequency goes down.

[Apogee]

Hey Marcus!

Congrats on getting it back online.

A couple of things:

Reduced freq will create more xformer heating due to longer time spent at the peak and trough of the sine wave.  Effectively, more time spent at max voltage = more heat.

I don't like the fact that the toroids are running that hot.  You are asking for burnout.  You should be able to hold your hand on them for about 10 seconds, anything less is too hot.

I would STRONGLY recommend changing the mounting of the toroids so they are not directly mounted directly on the plywood backboard.  At the very least your backboards should be painted with fireproof paint like we do in the telco/networking industry.  I feel like them running as hot as you describe coupled with them directly mounted to wood could be a recipe for disaster.

I love the fact that running at 450 rpm makes to so much quieter.  Also, the lower fuel consumption.  However, have you compared the "savings" against running it at 650 with the higher output?  My concern is the oiling system on these engines isn't the best, and I think it would live longer at the higher rpm.  In addition, your charging cycles would take less time = less overall time on the engine and gen head.  Food for thought...

In closing, I LOVE what you've done so far!  Awesome installation!

Best,

Steve

[Tom Reed]

Tis a thing of beauty you've got there! Perhaps speeding it back up to 650 rpm and turning down the field voltage on the st5 would gain a bit more efficency and allow those toroidal transformers to run cooler. You'd get more amps too.

[mbryner]

Good advice, Steve.   I have some leftover sheetrock that I can put behind them.   They aren't directly next to the wood -- actually about 1" away, hanging on shelf brackets.

Tom:  exactly what I was thinking to try next!    

What I didn't tell you guys was that I tried to run at full 650 rpm, but then the charge controller overdraws the engine.  Basically, the 'roid gets slowed down to the same approx 450 rpm by the load but the spring tension in the 650 rpm setup is higher, so it just injects more fuel.  Then it produces about 2500 watts at the charge controller, but the valves on the 'roid start to burn.  (!!!!)  It was dark outside so I couldn't see the exhaust smoke, but I could see smoke start to come out of the head.        

It seems the charge controller is triggering its draw amount on the voltage (well, it's a MPP controller), so as you recommend, Tom, decreasing the field voltage on the ST7.5 will decrease the output voltage to start with and run a little more efficiently.   I *really* like the low rpm sound.

If anyone has recommendations on an adjustable resistor for field voltage control I'm all ears.

Thanks.

[NevadaBlue]

It is good to hear the lady clucking again. Never tire of seeing stuff like this.
I don't understand (or want to... ) the torroids, but I like what I see in your power house.

[d34]

OK STOPPED POSTING THIS STUFF!!!!  Its making me sick with jealousy    



Just kidding.  Its like an addiction.  I log into this site way too many times a day.  Maybe someday I will get a simular setup running on my end. 

[Tom Reed]

Yes that fx80 will try and suck up every available watt and pump in into the batts.

[Crofter]

I think the field current is something around 3 amps at full load. Probably an automotive aftermarket heater switch would handle it and be adjustable. Not really insulated though to handle the voltage present. There are similar variable resistors used in the like of welding machines.