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PE-95G generator
c. 1944 PE-95-G Power Unit
Manufactured by the O’Keefe & Merritt Company of Los Angeles, California

This generator is powered by a Willy’s 4 cylinder gasoline engine rated at 35 horsepower at 1800 rpm. The engine speed is governed by a fly-weight mechanical governor that is driven by a V-belt from a pulley on the crankshaft. Accurate engine governing is important as it is engine speed that controls the frequency of the output voltage.

The PE-95-G is rated at 10 kW at unity power factor and 12.5 kVA at 80% power factor. Depending on the jumper settings, it will provide 120 or 240 volt at 60 Hertz.

Frequency regulation depends on the regulation of engine speed and is generally between .5 to 1 Hertz. After the engine warms up we have noticed this unit maintains its frequency between 59.5 and 60.5 Hertz.

The engine is not started with a conventional starting motor. It uses the exciter fields of the generator to spin the engine, causing it to start. Current, supplied by a standard automotive battery, is allowed to flow through the windings of the exciter in the generator. As the current flows the winding, the rotor, connected to the engine by a shaft, begins to rotate and after a few seconds the engine starts. In other words, during the starting sequence, the generator acts like a big electric motor! This engine, when starting, makes little or no noise as the engine rotates.

In the event there is insufficient current to turn the engine (it requires about 50 amps at 12 volts), a hand crank is provided in which to start the engine. Even when cold, it will often start with the first try.

Circa 1944 O’Keefe & Merritt Generator

The control panel of the PE-95 G generator.

O'Keefe & Merritt made these generators by the thousands for World War II but few, if any, actually made it to the front lines of WWII. This line of generators did see action in both Korea and Vietnam.

Mr. Gilbert Schwartz recalls seeing the PE-95 in large numbers for “just about everything that required electricity” while serving in the Marine Corps during the Korean War. “We used them to supply power for several types of large, tube-type radar units and for the power supply on the self contained 75 mm machine gun installations. We ran them singly or in banks for just about anything that needs their kind of electricity, which was most everything. [We] ran them almost continuously until we had to move them or they shot craps.”

Another source recalls them in Vietnam where they were used to provide power to field hospitals and other areas. One generator in particular ran nearly a year continuously. When that generator finally failed, it had nearly 25,000 hours on it! “Some of those generators had very hard duty imposed on the them, ...especially at firebases in the forward areas. [Our] team saw many with numerous bullet holes in them and some were only saved because of the heavy cast iron frames. They were heavy, but they were all military, over-built, simple, easy to maintain, reliable, and very plentiful.”

The PE-95-G also saw peace time duty. Mr. Ron Wood remembers one very while serving as Chief Engineer for radio stations KOWO-AM/KRUE-FM. “I did use this generator as a real power supply for the two transmitters on at least two occasions. The generator needed to supply about 7 kW and [it] handled that load nicely. It was very smooth (good governor action to hold the frequency smooth).”

KGB-FM/KPOP-AM gave this generator to the present owner to use at various old equipment venues and shows. This PE-95 also served as a backup generator at the KGB-FM/KPOP-AM transmitter site in San Diego, California.

The O'Keefe & Merritt PE-95-G generator has proven itself to be a capable, reliable and well built machine that has passed the test of time. This particular generator provides power during the Vista Show to power Ho de Do’s Laundry for the washing machine display. With some care, it should last for many, many years to come.


I have been asked over the years if I have a copy of the manual for the PE-95 series generator and I always had to say: "Well, I do and I can copy sections from it for you but I do not have the entire manual in a form that you can access easily." Now I am happy to announce the addition of the PE-95 manual for versions PE-95-A, PE-95-B, PE-95-C, PE-95-F, PE-95-G, and PE-95-H models. All these models are covered in one manual! I have scanned in the entire manual and created a PDF file. The manual is LARGE and I am sorry I can not make it any smaller but I did try to break it down to smaller pieces. I know a 45 MB file is hardly small. If you do not have high speed access I'd say start the process before bed and go away because it's going to be a while. Please note: You will need to download all three parts for the COMPLETE manual! Or... By popular demand, the entire manual in one easy download. The choice is yours and enjoy!

So here it is: Parts 1 through 3.

PE-95 manual Part One in Adobe Acrobat Format.

PE-95 manual Part Two in Adobe Acrobat Format.

PE-95 manual Part Three in Adobe Acrobat Format.


PE-95 manual COMPLETE in Adobe Acrobat Format.

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