I'm finally getting my generator project wrapped up.
I'm looking for ways for unattended shutdown in case of low oil pressure
conditions. What would be the easiest and cheapest way to accomplish this?
Either by shutting off the air or fuel supply? I'm sure you could use some
kind of "fuel line solenoid" to cut off the supply of fuel. Any ideas?
Thanks
Yea, how do you stop your engine now? What exactly happens when you
decide "it is time to stop the engine"? You probably press some button
or pull some lever, and then what happens?
i
Are you being a smart ass??? or am I reading your words incorrectly?
Let me explain how my engine has the speed lever set, you slide the lever
down and tighten a knob (twisting) that passes through the lever. If I was
NOT present to monitor the oil pressure and needed to shut it down to
prevent damage to engine, who would turn this knob to release the lever?
You?
This is why I was asking on how to go about doing this task? What method
would do the job and what parts could be used?
Thanks for your input.
That is a pretty crude mechanism. Cutting off fuel to the fuel pump may
take
a minute to shut the engine down, which seems too long. You need to
modify this
speed control mechanism so it doesn't require tightening knobs.
Probably the best,
if this engine is manually started, is to use a solenoid that will hold
the speed
lever in the right position when the juice is on, and drop it when power
is cut off.
Wire an oil pressure switch with normally closed contacts (normal in
this case
taken to mean oil pressure OK) in series with the solenoid and battery.
After starting
the engine and developing normal oil pressure, you pull the lever to
operating speed
and the solenoid holds it. If the solenoid burns out, the battery goes
dead, a wire
falls off from vibration, etc. the engine will be shut down. You could
wire a
normally closed push button in series with the rest of the parts as a manual
shutdown switch, so you don't have to overpower the solenoid to shut it off.
If this engine has an idle position to the speed lever, you have to make
sure a
spring or whatever pulls it all the way to the shutdown position on oil
pressure
failure.
Jon
you are reading my words incorrectly. The reason why I asked you how
you stop your engine now, is that the automatic stop mechanism would
need to do a similar thing to what you do manually. For example, when I
want to stop my onan DJE, I disengage the switch that supplies
electricity to the holding coil of the fuel shutoff solenoid.
That releases the solenoid, makes the solenoid push on the fuel
control lever, which shuts down fuel. The engine stops in 2 or so
seconds. Hence, automatic shutdown mechanism is doing the same thing,
namely, interrupts electricity to the holding coil.
If your stopping mechanism is different, then you would need a
different solution.
To know what method would do the job, it is important to know how the
job is done manually.
i
Then, let me apologize for any remarks that I wrote in regards to your
response. I'll post some pictures of the speed control on my engine
tomorrow.
Thanks.
Very gentlemanly of you to offer your apology. Ignoramus12712 is one of
the more polite people on the board and has shown very nice manners and
appreciates all concepts offered.
Harold
Indeed. I think the problem is, the issue being discussed
is reasonably complicated so that it requires a first-principles
approach.
This means asking specific questions that make no assumptions
at all. Unfortunately this sometimes makes the question asker seem
totally retarded.
I understand this effect well because I do it a lot at work.
Sometimes the only way to "get to the bottom of it" is to
look like a total retard. :^)
Jim
To stop a diesel you don't need to shut down the fuel, merely stop the
air flow. Worked for the diesel gen sets I ran in Vietnam and works for
an emergency shutdown for the 8V-92 Detroit in the bus here on campus.
Merely rig a flapper over the air intake (needs to be a positive seal)
that is spring loaded to close, use a solenoid to keep the trip
mechanism armed until oil pressure falls below a preset point, then trip
and let the flap stop all air.
You can buy a oil pressure guage with adjustable stop point so that you
stop at some point before zero pressure is reached. Avoid oil starvation
damage that way.
Georg V.
Yeah, but that's about the worst way to shut it down. The flap is for
killing a runaway engine, which is one of the charming properties of
Detroits.. Each time you use it you have to manually reset it (as it's
set up on the Detroit anyway, but you could set one up that resets
itself) and you'll put a lot of fuel in the oil doing it too.
John
Most of the 6-71 GM diesels that drove the smaller drilling rigs had air
shut of butterflies on the air intake manifolds. This was so that they
could be shut down even if natural gas came into the air intakes
insufficient quantities to keep it running if the fuel was shut off. It was
an important safety feature in the event of a blow out.
Apparently, it was as a result of a case where the diesels were shut off
during a blow out and didn't stop until a con rod came out of the side of
the crankcase and the ensuing sparks sent the whole lot up .
Regards
Tom
What you said is right on the mark, but wasn't the OP worried about
shutting down in the case of oil pressure loss?? That doesn't happen
unless something has gone badly awry and in my mind at least that calls
for stopping motion as quickly as possible to minimize damage. You
wouldn't want an automatic restart condition, rather you would want to
determine the cause and correct before a restart. And oil loss would
cause me to want to drain and check the lower end, if not more.
George V.
Ah, true. Somehow I took your original statement as a suggestion to use
this as a regular method of killing the engine. If set up with care,
such as ensuring that the crankcase vent wouldn't allow the engine to
continue running, it would likely work well.
John
Yep. I think that an approach of "let's figure out how a job is done
manually, and see if we can do the same thing automatically", is a
great first thing to try.
i
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