VALVE GP-SELECTOR & PRESS CONT 1841130 - Caterpillar

To set a specified amount of droop using an isolated bus for the load:1. Set the droop potentiometer to mid-position. (Use a 2K potentiometer, connected to terminal 14 (cw), 13 (wiper), and 15 (ccw).2. Start the prime mover and adjust the RATED SPEED potentiometer for rated speed with no load.3. Apply full load.*4. Adjust the droop potentiometers to give desired speed.
Figure 3-2. Droop Adjustment5. Remove the load and repeat steps 2 through 4 until engine speed returns to 60Hz when the load is removed.Example: Operating at 60Hz, 57 Hz at full load indicates 5% droop.*-If only 50% loading is possible, 58.5 Hz would indicate 5% droop. See Figure 3-3.To set a specified amount of droop on an infinite bus load:1. With the generator not paralleled, adjust the RATED SPEED (or speed trim) potentiometer to give a speed above 60 Hz by the percentage of droop required.Example: Droop of 5% would require raising the speed to 62 Hz.2. Mark the potentiometer position and re-adjust the RATED SPEED (or speed trim) potentiometer for 60 Hz. 3. Turn the external droop potentiometer full cw for maximum droop.4. Synchronize the generator with the bus and close the tie-breaker.
Figure 3-3. Droop Base Load with 5% Droop5. Return the RATED SPEED potentiometer to the mark made in step 2.6. Load the generator by turning the droop potentiometer counterclockwise until full load is achieved.7. Unload the generator by turning the RATED SPEED (or Speed Trim) potentiometer ccw until no load is achieved.8. Open the tie-breaker and repeat steps 1 through 6 until no further adjustment of the external droop is required in step 6. * Droop is 10% per volt.* Auxiliary is 3% per volt.* Synchronizer Input is 0.667 of 1% per volt.* Speed Trim is 10% per volt.Chapter 4. Description of Operation
Introduction
The 2301A Speed Control monitors prime-mover speed and maintains it at the correct operating level. With the addition of a load sensor the system will share the load with other generators when two or more systems are running in parallel.Speed Control
The system, as shown in Figure 4-1, consists of:* A magnetic pickup (MPU), to sense the speed of prime mover.* A frequency to voltage converter, to convert MPU frequency to a voltage for use in the 2301A internal circuits.* A speed reference to which the prime mover speed is compared. (Idle and Rated speed references are provided by the 2301A Speed Control. The speed reference being used is selected by the operator with an external switch.)* A speed summer/amplifier with an output proportional to the amount of fuel or steam required to maintain the reference speed at any given load* An actuator to position the fuel or steam mechanism (injector rack or steam valve) of the prime mover.
Figure 4-1. Speed Control SystemThe MPU generates an ac signal with a frequency proportional to prime-mover speed.The frequency-to-voltage converter receives the MPU frequency signal and changes it to proportional dc voltage.The speed-reference circuit generates a dc reference voltage to which the speed signal voltage is compared.The