LXi-2900 Electric Fire Pump Controller with Transfer Switch Wye Delta Open Transition

Hubbell Fire Pump Motor Controllers with Automatic Transfer Switches (ATS) are designed to comply with the latest standard of the National Fire Protection Association for the installation and operation of centrifugal Fire Pumps (NFPA-20).Model LXi-2900 is a combined automatic and manual wye-delta reduced current fire pump controllers applied where the capacity of the power source does not permit across-the-line starting of the motor. The controllers are used with special six (6) or twelve (12) lead squirrel cage motors designed for wye-delta starting.The motor is started connected in wye, drawing approximately 33% of the locked rotor current and producing approx. 33% of its locked rotor torque. After a short time delay, the controller transitions the motor to the delta connection. The motor current & torque jump to the across-the-line current & torque at the speed at which the transition takes place. The current quickly falls to its normal running current as the motor accelerates to full speed.The difference in the LXi-2800 and LXi-2900 is the transition between the wye and delta connections. The LXi-2900 has open transition between the wye and delta connections. This condition can cause current surges or disturbances back into the power source and can affect the operation of other equipment.The LXi-2800 has closed transition between the wye and delta connections through the use of an additional contactor and resistor. The LXi-2800 provides a smoother transition by keeping power on the motor during the transition.