Laserfiche WebLink
C. Operation <br />1. Accomplish speed control by adjusting both the output voltage and frequency to the <br />motor. Convert input AC power to a constant voltage DC which is then converted to <br />adjustable voltage and frequency three-phase AC utilizing pulse width modulation <br />technology to operate the connected motor at the desired speed. The VFD shall not <br />induce excess power losses in the motor. The VFD shall not produce voltage impulses <br />deemed harmful to the motor insulation by the motor Manufacturer. <br />2. Each VFD shall be specifically designed for use with variable torque pumping loads. <br />Soft -start control circuitry shall limit in -rush current, not to exceed 100 percent of motor <br />full load current, under all manual and automatic operating conditions. When power <br />outages occurs, the drive system shall shut down in an orderly manner. Upon restoration <br />of A.C. power, the motors shall restart sequentially and run at a rate depending upon the <br />reference requirements, by the sequencing logic controller. <br />D. Ratings <br />1, Line Voltage: 460 volts, three-phase, (+/-) 10 percent continuous. <br />2. Line Frequency: 48-62 Hz. <br />3, Ambient Temperature: 0 degrees C to 40 degrees C. <br />4, Altitude: Up to 3300 feet above sea level. <br />5. Maximum Transient Current Variable Torque: 1.00 continuous, 1.10 one minute; <br />Constant Torque: 1.00 continuous, 1.50 one minute <br />6. Power Factor: Minimum 0.95 throughout speed and load range. Power factor correction <br />by capacitors shall not be acceptable. <br />E. Performance <br />1. Efficiency. Above 97 percent at 100 percent output frequency (full speed) and full load <br />as well as above 95 percent at all reduced load and speed conditions between 40 and 100 <br />percent output frequency. <br />2. VFD Inrush Current: Limited to less than 100 percent of motor full load current. <br />3. Duty Cycle: 6 starts per hour. <br />4. Output Frequency Range; 6 hertz to 60 hertz, cogless, with adjustable minimum and <br />maximum to match the required operating conditions. <br />5. Output frequency stability (+/-) 1.0 percant� continuous <br />6. Pulse Width Modulation (PWM) controller carrier frequency regulation shall be designed <br />for "quiet" motor operation. Induced motor noise when operating at full speed and load <br />on VFD shall not exceed 5 dBA above the measured motor noise level when operating <br />044572017 <br />16483-4 <br />