Class1 Pump Throttle Electric Cotnrol Series 2 - Manual (Page 9)

9
PTEC II
SYSTEM OPERATION
The governor will NOT operate unless the RDY light is illuminated on the Control Panel. If the
ready light is not on, it indicates a problem with the interlock circuits or wiring.
Once the Ready Light is on, the pressure governor becomes operational when the Govern
Switch is toggled to the ON position. The ACTIVE Light on the Control Panel will then be
illuminated and the system will be active. The system will control the throttle to maintain
either engine speed (RPM Mode) or Pump Pressure (PSI Mode). Whenever the Govern
Switch is turned off, the Actuator Interface will return the actuator to its idle position.
RPM MODE
When the Mode Switch is in the RPM Position, the PTEC II will control the throttle to maintain
the engine speed attained with the INC/DEC Switches or the current engine speed if the
Mode Switch is toggled from PSI to RPM. The engine speed can be changed by using the
INC or DEC switches. The engine speed obtained when the INC/DEC switch is released will
become the set speed and the system will provide throttle control to maintain this speed.
PSI MODE
Whenever the Mode Switch is in the PSI position and the Govern Switch is on, the system will
provide pump pressure control using the linear actuator to adjust engine speed. The set
pressure can be adjusted using the INC or DEC switches to achieve a new operating pressure.
The pressure is monitored with a 300 PSIG transducer located on the discharge side of the
pump.
PUMP CAVITATION
If discharge pressure drops below 30 PSI for 5 seconds, the actuator will be returned to idle.
The INC switch must be toggled to increase engine RPM (pump pressure) after this event.
SWITCHING MODES
The PTEC II can be changed from RPM to PSI or PSI to RPM Mode without going to Idle.
The setpoint becomes either the current engine speed or pump pressure at the time of the
change as appropriate.
MECHANICAL FORCE to IDLE
The Actuator Interface Module contains a relay that is activated with the Park Brake. Whenever
this input is lost the actuator is forced to its maximum extension.