Part No. 65196 Genie S-60 & Genie S-65 3 - 1Section 3 • Theory of OperationThird Edition • First PrintingTheory Of OperationPower SourceThe Genie S-60 and Genie S-65 are powered byeither a Gasoline/LPG engine or one of two dieselengines. The Gasoline/LPG option uses a FordLRG-425 EFI rated at 70 horsepower @ 2500rpm. The diesel options include a DeutzF4L1011F rated at 56 horsepower @ 3000 rpm,and a Perkins 704-30 rated at 63 horsepower @2600 rpm.Hydraulic SystemAll machine functions are performed by thehydraulic system. The hydraulic system is dividedinto two groups: Boom/Steer functions and Drivefunctions.Boom/Steer functions are powered by a single-section gear pump, rated at 12.3 gpm(46.6 L/min). When the engine is running, thispump supplies hydraulic fluid under pressure tothe function manifold, where the directional andflow control valves are located. To protect fromover-pressurization of the Boom/Steer system, thepump is provided with a pressure relief valve, setat 2900 psi (200 bar) on S-65 Models, and 2600psi (179 bar) S-60 Models.Drive functions are powered by a bi-directional,variable output piston pump rated at 0 to 30.3 gpm(0 to 114.7 L/min) @ 2500 rpm. Two internal 3500psi (241 bar) relief valves are used to preventover-pressurization of the closed loop drivesystem.The boom lift cylinder, boom extend cylinder,platform leveling slave cylinder, platform rotatorand jib boom cylinder (S-65 models) incorporatecounterbalance valves to prevent movement in theevent of a hydraulic line failure.Electrical SystemBoom/Steer functions are accomplished bymoving a toggle switch or a controller, whichsends voltage to the appropriate directional controlvalve. These directional valves determine whichdirection the hydraulic fluid will travel. The volumeof hydraulic fluid is determined by either aproportional valve or flow regulator valve. Aproportional valve receives a variable voltagesignal and delivers more hydraulic fluid as thevoltage increases. A flow regulator valve is amechanical valve and delivers a predeterminedamount of hydraulic fluid.Drive forward or reverse is accomplished bypressing down the foot switch in the platform andmoving the drive controller (joystick) in theappropriate direction. When activated, the drivecontroller completes a circuit to the ElectronicDisplacement Controller (EDC). The EDCregulates drive pump displacement in directrelation to the drive controller position. Ahorsepower limiter printed circuit board (located inthe platform control box) is provided to maintainengine RPM as drive system loads becomegreater. This is done by sensing engine RPM (viaan AC tap on the alternator) and limiting theamount of current supplied to the drive controller/EDC, which destrokes the pump, reducing pumpoutput.
