Turbomachinery Package Specification

Titan 250 Generator Set

 

 

6.2.2Variable Frequency Drive

The VFD (Figure 7) is a motor speed controller that provides pulse-width modulated power with variable frequency and voltage to the starter motor. Controlled by the Turbotronic 4 control system, the VFD regulates voltage and frequency to the starter motor to control engine speed from standstill to starter dropout speed. The system is capable of performing up to six start attempts per hour, as well as extended purge cycles for heat recovery unit applications and engine wash cycles. The VFD cabinet is designed for installation in a non-hazardous location. Electrical disconnects and overcurrent protection devices are not provided.

6.2.3Power Wiring

The start system (Figure 8) requires customer-furnished, three-phase AC input. Additional three-phase AC power wiring is required to connect the VFD to the starter motors. A start contactor is not required for VFD operation. A customer-furnished fused disconnect at the VFD input is recommended. Optional motor space heater wiring is available.

Figure 8. Typical Direct-Drive AC Start System

6.3Backup Slow Rotation System

The Titan 250 package is equipped with a DC powered turning gear system (Figure 9) to ensure low speed rotation of the turbine as backup for the DAC starter motor in the event of loss of AC power to the package. The system engages the decelerating turbine at low speed and maintains rotation for a specified time.

Figure 9. Turning Gear Assembly

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TPS250GS/908 - Preliminary

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