CAT Titan 250 Manual De Usuario

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Turbomachinery Package Specification 
Titan 
250 Generator Set 
6.2.2 
Variable 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. 
6.2.3 Power 
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 
 
6.3 
Backup 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 
 
© 2008 Solar Turbines Incorporated. All rights reserved. 
TPS250GS/908 - Preliminary 
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