BEARING AS-TAPERED ROLLER 3499891 - Caterpillar

Introduction
This manual describes the Woodward 721 Digital Speed Control, models 9905-291 (low voltage), 9905-381 (high voltage), and 9905-466 (consists of model 9905-291 with an 8272-720 Real Power Sensor).
Read this entire manual and all other publications pertaining to the work to be performed before installing, operating, or servicing this equipment. Practice all plant and safety instructions and precautions. Failure to follow instructions can cause personal injury and/or property damage.The engine, turbine, or other type of prime mover should be equipped with an overspeed (overtemperature, or overpressure, where applicable) shutdown device(s), that operates totally independently of the prime mover control device(s) to protect against runaway or damage to the engine, turbine, or other type of prime mover with possible personal injury or loss of life should the mechanical-hydraulic governor(s) or electric control(s), the actuator(s), fuel control(s), the driving mechanism(s), the linkage(s), or the controlled device(s) fail.
To prevent damage to a control system that uses an alternator or battery-charging device, make sure the charging device is turned off before disconnecting the battery from the system.
Electronic controls contain static-sensitive parts. Observe the following precautions to prevent damage to these parts. * Discharge body static before handling the control (with power to the control turned off, contact a grounded surface and maintain contact while handling the control).* Avoid all plastic, vinyl, and styrofoam (except antistatic versions) around printed circuit boards.* Do not touch the components or conductors on a printed circuit board with your hands or with conductive devices.
Application
The 721 Digital Speed Control controls the speed and load of reciprocating engines in generator set service, including those with flexible couplings (see Figure 1-1). The control includes inputs for two magnetic pickups (MPUs) or proximity switches for monitoring flexible coupling torsionals, an input for a 4 to 20 mA remote speed or load setting, an input for output fuel limiting, an internal speed reference for local control of speed, and an input for a KW load sensor and load sharing connections for load sharing applications.* a 721 Digital Speed Control;* an external power source;* one or two speed-sensing devices (as required);* a proportional actuator to position the fuel rack;* a terminal for adjusting control parameters;* an optional KW load sensing device;* an optional boost pressure or rack position sensing device for fuel limiting.
Figure 1-1. Flexible Coupled Generator SetThe 721 control (Figure 1-2) consists of a single printed circuit board in a sheet-metal chassis. Connections are via three terminal strips and a 9-pin subminiature D connector.Control Options
The 721 control requires the following power supply input voltages, with 18 watts as the nominal power consumption at rated voltage: * low voltage - 18-40 Vdc (24 or 32 Vdc nominal);* high voltage - 88-132 Vac 45-65 Hz (120 Vac nominal) or 90-150 Vdc (125 Vdc nominal).Discrete input voltages provide on/off command signals to the electronic control, such as Raise Speed/Load, Lower Speed/Load, etc. Each discrete input requires 10 milliamps at its 24 Vdc nominal voltage rating (for 24 volt switching logic).Other control options are: * proximity switch