SHIM 7Y2496 - Caterpillar

Chapter 3. Operation and Adjustment
Initial Pre-Start Settings
-OVERSPEEDOverspeed with resultant equipment damage, personal injury, or death is possible when setting up a control system. Read this entire procedure before starting the prime mover for the first time.
CAUTION-DO NOT TURN POTS BEYOND THEIR STOPSThe Rated Speed Potentiometer is the only multi-turn pot in this control. All other pots are single-turn. Take care not to turn these pots beyond their stops.
1. RATED SPEEDa. Set the RATED SPEED potentiometer to minimum (fully counterclockwise in ten-turn potentiometer).b. Set the external SPEED TRIM, if used, to mid-position.2. RESET- Set at mid-position. (One-turn potentiometer).3. GAIN- Set at mid-position. (One-turn potentiometer).4. RAMP TIME- Set at minimum (fully ccw, one-turn potentiometer- be careful not to overtorque the pot ).5. LOW IDLE SPEED- Set at minimum (fully ccw, one-turn potentiometer- be careful not to overtorque the pot ).6. DROOP- Set optional external droop (if used) at minimum (fully counterclockwise, one-turn potentiometer- be careful not to overtorque the pot ).7. ACTUATOR COMPENSATION (One-turn potentiometer)a. DIESEL, GAS TURBINE, FUEL-INJECTED GASOLINE PRIME MOVERS: Set the ACTUATOR COMPENSATION potentiometer at 2 on the 0 to 10 scale.b. CARBURETED GAS OR GASOLINE or STEAM TURBINE PRIME MOVERS: Set the ACTUATOR COMPENSATION potentiometer at 6 on the 0 to 10 scale.8. START FUEL LIMIT- Set at maximum (fully cw one-turn potentiometer- be careful not to overtorque the pot ).9. Be sure the actuator is connected to terminals 9 (+) and 10 (-).Start-up Adjustments
1. Complete the installation checkout procedure in Chapter 2, and the initial prestart settings above.2. Close the Close for Rated contact. If the external droop feature is being used it should already be set at isochronous, fully ccw be careful not to overtorque the pot). This is for initial prime mover start-up only. For normal start-up, the Close for Rated contact should be open if the prime mover is to start at idle.3. Apply input power to the control.4. Preset rated speed.If a signal generator is not used, set the RATED SPEED potentiometer at minimum (fully counterclockwise).If a signal is not used set the signal for the frequency of the speed sensor at rated speed, and connect it to terminals 7 and 8. (The rated speed frequency in Hz equals the rated engine speed in RPM times the number of teeth on the speed sensing gear, times the ratio of engine speed to speed-sensing-gear speed, divided by 60.) Put the Close For Rated contact in rated (closed) position set the speed trim potentiometer (if used) to mid position. Connect a dc analog voltmeter to terminals 9 (+) and 10 (-) to read actuator voltage.If the actuator voltage is at minimum (about 0 volts) slowly turn the RATED SPEED potentiometer clockwise (counterclockwise for reverse acting controls) until the voltage just begins to move toward maximum.If the actuator voltage is at maximum, slowly turn the RATED SPEED potentiometer counterclockwise (clockwise for reverse acting controls) until the voltage just begins to move toward minimum.Continue to very slowly adjust the RATED SPEED potentiometer in the appropriate