Chapter 1. General Information; 2301 Electric Governor; Proportional Actuators For 2301 Electric Controls - Woodward EG-3P Installation And Operation Manual

EG-3P Actuator Manual 82560
Chapter 1.
General Information

2301 Electric Governor

The 2301 electric governor is one in which its actuator output (terminal) shaft
position is directly proportional to the input signal from its electric control unit. It
can be used in an isochronous (constant speed) mode for single engine
operation or when paralleled with similar units on an isolated bus. It can also be
used in the droop mode for paralleling dissimilar units or operating on an infinite
bus. The 2301 governor is used in the same type of service as many other
governor models. It is particularly well suited, when used with some types of
proportional actuators, to engines operated in tandem to drive a common load. In
such installations, one electric control is used to furnish the same input signal to
the proportional actuator on each engine. Since each actuator receives the same
current, their output shafts take the same position and give each engine the
same amount of fuel.
The 2301 electric governor consists of an electric control unit, a speed setting
potentiometer, and a hydraulic actuator. The electric control receives the input
signals to the governor; its output serves as the input signal to the actuator. The
actuator output controls the flow of energy medium to the prime mover. The
speed setting potentiometer, used to adjust speed setting, provides one of the
inputs to the electric control.
The operation of the 2301 type governor is different and distinct from other
electric governors. The steady-state output of the electric control is a level of
voltage determined by the actuator terminal shaft position required to maintain a
particular load on the prime mover. The voltage is always the same polarity. This
type of control unit requires an actuator in which the output shaft takes a position
proportional to the voltage of the input signal.
In contrast, the electric control unit of the EG series electric governor emits a
nominally zero signal during conditions of on-speed, steady-state operation, and
larger voltage signal only during off-speed or load-changing periods. In this type
of system, the direction of actuator operation depends on signal polarity.
As is the case with any type governor, the prime mover should be equipped with
a separate overspeed device to prevent runaway if a failure should render the
governor inoperative.

Proportional Actuators for 2301 Electric Controls

Among the proportional actuators used with the 2301 electric controls are:
EGB-2P Actuator
This is a proportional actuator that has a mechanical-hydraulic backup governor
section as well as an electric-signal-operated governor section. It must be driven
directly from the prime mover for speed sense to the flyweights and operation of
the governor oil pressure pump. The EGB-2P actuator has a stalled work
capacity of 2.5 ft-lb (3.4 J) at a 32° output shaft travel. Useful work capacity is
about 2/3 of stalled capacity.
6 Woodward