Generator Set Control Panel for Switchgear Conversion Caterpillar

The control board provides overspeed protection by monitoring the speed of the engine. The magnetic speed pickup tells the control board the speed of the engine. The magnetic speed pickup (MPU) tells control board the engine speed. The overspeed setpoint can be set for either 118% of rated speed or 125% of rated speed. The setpoint must also be adjusted for a precise setting. The "SW2" switch is used to select the overspeed setpoint. The "OSSET" potentiometer is used in conjunction with the LOCAL indicator to adjust the selected overspeed setpoint.

Note: The "OSSET" potentiometer should be adjusted. When the engine is at rated speed, adjust the "OSSET" potentiometer so that "LOCAL" is just illuminating or extinguishing. The "LOCAL" indicator will illuminate under the following conditions:

• the engine speed is less than the overspeed setpoint.

• the engine speed is equal to the overspeed setpoint.

If the engine speed is greater than the overspeed setpoint or equal to the overspeed setpoint, the "LOCAL" indicator will not be illuminated.

Procedure to Adjust the Overspeed Setpoint

1. Start the engine and adjust the RPM to rated speed.

2. Locate "SW2", "OSSET", and "LOCAL" on the control board.

3. Set switch "SW2" to the desired position.

   Position 1 - 118%

   Position 2 - 125%

4. Observe "LOCAL".
   • If "LOCAL" is ON, turn "OSSET" potentiometer counterclockwise until "LOCAL" turns OFF.

   • If "LOCAL" is OFF, turn "OSSET" potentiometer clockwise until "LOCAL" turns ON.

5. Once the proper setpoint has been located, adjust "OSSET" potentiometer until "LOCAL" is just turning ON.