overspeed switch

[airhigh64]

Hello everybody! Just joined up, have been lurking on this site for awhile and it sure looks like where I can find out info, thanks ahead.
I have purchased a rebuilt White/Hercules D198ER. Appears a lot of the engine function devices are installed. oil pressure, water temp, oil pressure, the problem I have is with the overspeed switch, need to know the workings of this device. The NSN # is 5930-01-537-9648. Will be mating this engine to a 25 KW 2-bearing generator. Really would need to get this switch working properly.

 

[Guyfang]

You should look at a schmatic for maybe the MEP-004, MEP-005 or MEP-006 gen set. Normally, the speed switch, (S-9) description is in any of the TM's for the aforementioned gen sets.

A short description, The S-9.1 contacts are reversing contacts. One set is normally closed. They open, and cut the starter out, at a predetermined RPM, to prevent the starter grinding on the flywheel. The other S-9.1 contacts, close at the same time to send 24 volts to the A.C. volt exciter/regulator, to light off the main generator. S9-2 contacts are not used, (but could be). S-9.3 contacts, are a normally closed contacts, that only open at a predetermined RPM to stop the gen set from overspeeding. The RPM and other info is in the TM's it's been too long ago for me to remember.

Did that help? If not, tell me what is important to know.

Good engine. Runs sweet.

Take care,
Guy Wiltfang

 

[airhigh64]

Thanks for the pointing me in the right direction with this switch. I will be looking up info in the TM.