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PGG-EG governor/actuators have motor speed setting of the ballhead backup governor. The units are normally used on generator applications. Externally adjustable droop on the backup governor and load limit are standard on the PGG-EG.
Setting the speed of the mechanical governor slightly higher than the maximum speed under electronic control causes the mechanical portion of the PGG-EG to always seek a fuel setting higher than the electronic control. Electrical control thus controls the fuel position because of the least-fuel-selection feature.
Should the electronic signal to the reverse acting PGG-EG fail, due to some problem in the system, the electric actuator will call for an increased fuel position, above the setting of the mechanical governor. At this point the mechanical speed setting is lower, and the ballhead controls the engine-fuel setting.
PGG governor/actuators are available with any of the PG output systems. Output ranges from 16 N?m (12 lb-ft) maximum work capacity to 678 N?m (500 lb-ft), depending on the governor operating pressure and the output options selected. Most outputs provide 30° of rotary travel (25 mm [1 inch] of linear travel is also available).
PGG-EG governors may be equipped with lube oil pressure and water pressure alarm and shutdown.
The PGG-EG governor/actuator combines the proven dependability of the hydro-mechanical PG governor with the flexibility of an electronic control. The PGG-EG is used to control speed or power output of engines where remote speed-setting capabilities with speed droop on the mechanical side of the governor are required.
The governor has a self-contained oil supply. PGG-EG governor/actuators are available for clockwise, counterclockwise, or reversible drive rotation. Oil pressure is maintained by a relief valve and accumulators. Oil flow to and from the governor power cylinder is controlled either by a centrifugal flyweight and pilot-valve-plunger assembly or by an electronically controlled torque motor and a follower-type pilot valve. The power cylinder is mechanically linked to, and positions, the fuel rack or valve.
Droop in the PGG-EG is set with a dial on the front panel. It is adjustable from 0 to more than 8%. Droop on the PGG-EG is determined by a combination of the dial setting and the position of the governor output cylinder. This allows the mechanical speed to be set closer to the electronic speed than is possible in other “ballhead backup” governor/actuators.
Adjustable load limit makes the PGG flexible in its ability to back up the electrical control and still not overspeed or overload the engine should the electronics fail.
Product Specification 36635