Specifications include, but are not limited to: This solicitation is for 2 types of variable frequency drive (VFD) controllers. One type must be able to convert must be able to convert 208 volt, three-phase, 60 Hertz utility power to adjustable voltage (0–208 V) and frequency (0–60 Hz.) three-phase AC power for stepless motor speed control with a capability of 10:1 speed range. The second type must be able to convert 480V, three phase AC power for stepless motor speed control with a capability of 10:1 speed range. Each requirement in this bid applies to both types of VFD motor controllers. The variable frequency drive shall be a Pulse-Width Modulated (PWM) design with diode bridge input (SCRs are not acceptable) and IGBT output. Modulation methods which incorporate “gear-changing” techniques are not acceptable.
