CS compression valve question ?

[compig]

Was looking over my recently acquired SOM plant and a question suddenly raised itself. My understanding of the SOM is that it starts and stops itself automatically and without attendance. If I understand the function of the compression changeover valve correctly it needs to be screwed in to start and out for running at anything over 1/3 load. No linkage is evident to make the operation of the CCOV automatic for unattended operation so whats the deal here ?

Please excuse me if this seems a stooopid question but I'm on a steep learning curve here !!

[listerdiesel]

The difference is that you have a 'starter motor' turning the engine over quicker than you can turn it by hand, so the compression change-over isn't as necessary.

The instruction book does say to use the change-over valve for hand starting.

Interestingly, the Lister CE Post office genny sets had solenoids on the change-over valves.

Copy of the SOM manual is on our website.

Peter

[contaucreek]

That wasn't a stupid question.Stupid is me at my first engine show marvelling at the thoughtfullness of some engine owners to put screens on their cooling tanks so the water wouldn't splash on people 

[LowGear]

Are you saying that the cooling tanks aren't wishing wells?

[compig]

LOL !!   

[compig]

The difference is that you have a 'starter motor' turning the engine over quicker than you can turn it by hand, so the compression change-over isn't as necessary.

The instruction book does say to use the change-over valve for hand starting.

Interestingly, the Lister CE Post office genny sets had solenoids on the change-over valves.

Copy of the SOM manual is on our website.

Peter

Thanks for that Peter. It did cross my mind that may be the reason , but second oppinion is always valuable and fills in the gaps.

[aqmxv]

If it wasn't bombed during the blitz, somewhere there's a piece of paper that specifies the minimum cold start temperature the post office gen sets had to manage.  Since it was a cost-added component, it's a safe assumption that Lister wouldn't have added it unless the engine wouldn't dependably start at the required temperature regardless of fuel or cold-soak time.

One sees a lot of this kind of overkill in military/critical services applications.  It's one of the reasons that things are so expensive when bought on government contract - the customer dictates the critical limitations of the device, instead of the marketplace.

[compig]

Was looking over the beast today and found the answer to the SOM starting issue. It has an decompressor solenoid acting on the exhaust valve. So the cold start valve is permanently screwed out unless it needs starting by hand.