Woodward ProAct I and II

Digital Electric Powered Governor System

Part number: 8400-016



The ProAct™ digital control system is an electric powered governor system designed to provide precise electronic control and limiting for gas and diesel engines. ProAct I is designed for direct coupling to the butterfly valve shaft on small gas engines or for diesel engines which require less than 1.4 Nm (1.0 lb-ft) of torque to move the rack. ProAct II is designed for control of most diesel engines and larger carbureted gas engines.



Woodward ProAct I and II driver Digital Electric Powered Governor System


The ProAct control system is a combination of a 16-bit microprocessor control and a limited-angle rotational torque motor (actuator). The system features user-friendly menus to provide extreme flexibility in the development of special control schemes for different types of engines.

Two different ProAct actuators are available. The ProAct I actuator provides 1.4 Nm (1.0 lb-ft) of torque in steady state and 3.55 J (2.62 ft-lbs) of work over 75° of travel. The ProAct II provides 2.7 Nm (2.0 lb-ft) of torque in steady state and 7.11 J (5.24 ft-lbs) of work over the 75° of rotation.

The control has two complete sets of dynamic adjustments to aid when operating with such conditions as two different fuels, or in parallel/stand-alone electrical generation. A four-slope gain schedule is available in each set of dynamics. This permits programming for extremely responsive yet extremely stable operation of carbureted engines. Adjustment of the ProAct control is done through a hand held programmer. The programmer allows access to all of the tunable items. The programmer is separate from the control, and will normally be unplugged and removed during governor system operation. This provides security against unauthorized tampering with system adjustments. The control may be tuned or monitored with a PC rather than with the hand held programmer, if desired.

Standard Features

The ProAct digital electronics include settings for either droop or isochronous operation. Start, idle, and rated speeds may be set. Separate droop schedules are available for rated and idle. Variable speeds may be controlled by external input. The rates that the speed setting can be raised or lowered may also be adjusted. Fuel limits may be imposed for No Load, Full Load, Start-up (start-fuel limit), and Idle speed. A two-slope torque limit is available. Separate ramp times may be established for acceleration and deceleration. Speeds for rated, idle, raise limit, and lower limit are also easily preset.

Special features

• 75° rotary output allows direct coupling to butterfly, eliminating linkage

• All-electric actuator requires no drive or  hydraulic supply

• Programmable digital electronics permit tailoring control to various applications

• Actuators are extremely fast, electronically positioned in both directions

• Alternate dynamics for dual fuel applications or cogen/standby

• 3 speed-activated switches

• Start fuel limit and maximum fuel limit for derating

• Manifold pressure fuel limiting

• Two-slope torque limiting