Micro CoGen.

Hey J

I'll send you some pics shortly.  I think a one wire solenoid engages when power is applied. So you push a shut down button,it sends 12volts, the solenoid turns fuel off.  I used a two wire solenoid. One wire is a PULL wire and is high amps to overcome the governor springs. The other wire is a hold wire that is very low amps and just holds the fuel open.  I ran the hold wire to my key switch so that it gets voltage when key is on. I hooked the pull wire to my starter solenoid. When i crank engine the pull wire turns fuel on and the hold wire does its thing. Turn the key off the hold wire disengages and it dies.  Simple but works great.  Buy your solenoid on ebay. New ones are costly

If you want to use the one wire solenoid you could put a spring on the governor to keep the fuel on at all times. Apply 12 volts to the solenoid to turn fuel off.  In this way you could get a cheap oil pressure switch (10 bucks) and a temp switch (10 bucks) and hook them in series to the solenoid. Apply 12 volts to the solenoid and if either switch hits its limit the circuit is completed and solenoid shuts down. In retrospect i wish i would have done it this way and avoided the relays etc.

Southwest Louisiana

I built/use a 10KW using a Kubota D722. its a great setup The electrical is really simple and i can send you pics and explanations if you like. I used a Woodward brand shutdown solenoid and made my own bracket. I used murphy swichgage for oil and water but honestly i would not do the oil again.  Let me know if you want pics of the unit or other info. glad to help.

1. what prime mover are you using or planning to use?  Kubota d722 3 cyl diesel

2. what hp or kwatt (mechanical) output is the prime mover?    20 HP

3. what generator are you using? AC only? DC only? or both?   AC 

4. how long have you had the unit?     3 years

5. how long does it run or are you planning to run,  per day, week, month or year? 20 or 30 hrs/yearly

6. is the unit used for primary power, backup, emergency, or?   emergency

7. do you harvest the waste heat and use that heat?  if so for what purpose? domestic hot water
production, space heating or both?  Do not harvest waste heat

8. if you are not harvesting the waste heat, are you planning to do so?  do you have any interest in doing so?  No interest at this time

9. do you use any form of automation, such as autostart? Manual start.  Murphy switches on everything else for shutdown

10. if you do not use automation, would you do so if it were commonly available and reasonable in price?  No.   I like manual start.  Need to hear "noises" should  they be present

11. how would you rank fuel efficiency of a unit, not very important, somewhat important, moderately important, very important, or most important. Moderately important

now a couple of other questions

12. where do you find the information you rely on to make decisions about your genset designs? Years of looking at different designs. Lots of informal research.

13. do you feel that there is enough information available to you to make good decisions regarding design? Yes

14. if you are frustrated or find it difficult to find information, what sorts of information would you like to find? N?A

15. if there was a book available on some facet or facets of power generation for offgrid applications such as what is typical on this forum, what would you find as being a must have or rather what would you like to see in such a book?