Figure 1-3. Solenoid Shutdown Connection - Woodward EGB-1P Installation And Operation Manual

Manual 82570
Two factors are of primary importance in utilizing external solenoid shutdowns.
First is the location of the solenoid. Figure 1-3 following shows the proper
connection. Once a suitable connection is decided, the solenoid must be
connected with tubing runs as short as possible. The solenoid must also be
mounted below the governor and oriented so that it does not fill with air. Air
trapped by the tubing causes governor instability.
The second consideration is solenoid size. The solenoid and all connected tubing
must pass enough flow to ensure that the governor moves to minimum position
and remains there. Shutdown of the EGB-2P Governor/Actuator is accomplished
by draining oil from the increase fuel side of the compensating land on the
actuator pilot valve. This forces the pilot valve to drain control oil to move the
power piston to minimum fuel. Since this is a restricted flow, the solenoid for the
EGB-2P must flow 0.6 US gal/min (2.3 L/min) with a maximum pressure drop of
10 psi (69 kPa). Therefore, different flow capabilities are required depending on
rated governor speed.
The shutdown solenoid can be used for normal shutdown and/or as a backup to
the safety shutdown system. The engine, turbine, or other type of Prime Mover
should be equipped with safety systems entirely separate from the governor.
However, the safety system may be interfaced with the shutdown solenoid to
cause the governor or actuator to go to minimum during safety systems
shutdown. As with all safety shutdowns, proper operation should be confirmed
periodically. See the prime mover manufacturer's instructions.
Woodward

Figure 1-3. Solenoid Shutdown Connection

The shutdown solenoid must not be used as an overspeed protective
device. Overspeed protection must come from a unit completely
separate from the EGB-2P or -1P control.
EGB-1P/-2P Governor/Actuator
5