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Packaged AC Drives

Packaged AC Drives
Class 8839 PowerGard™ Type CPD

Class 8839 PowerGard AC drives are the most effective means for harmonic abatement of adjustable speed drive applications available in the industry. The power quality initiative of PowerGard AC drives includes cancellation of the 5th, 7th, 11th, 13th harmonics and attenuation of other harmonics using its patented 18-pulse phase shifting transformer design.

Not all multi-pulse designs are created equal

Unlike many competitive offerings that use adaptations of harmonic trap filters, 12-pulse autotransformers and hybrid multi-pulse schemes, the PowerGard incorporates a truly dedicated and balanced converter design to cancel harmonic currents common with 6-pulse pulse converter loads. Integral to one enclosure, the PowerGard AC drive integrates a 5% line reactor in series with a phase shifting transformer to provide enhanced transient protection and rectifier load sharing benefits. The fork transformer includes a delta tertiary winding that enhances symmetrical operation under unbalanced line voltage conditions over competitive designs. Our design eliminates the need for inter-wiring of separately mounted equipment, thus reducing installation cost.

The packaged PowerGard drive utilizes the Altivar® 66 AC drive family for reliable speed control of large pump and fan applications, and meets IEEE 519-1992 guidelines when measured at the input terminals.

Available Ratings

• 100 - 350 HP constant torque, 460 VAC, three-phase input
• 125 - 400 HP variable torque, 460 VAC, three-phase input

PowerGard AC drives are designed to:

• Increase power distribution capacity by reducing the input "rms" current demand
  - meets IEEE 519-1992 guidelines for current distortion at drive input terminals
• Reduce power quality problems and prevent nuisance tripping of sensitive electronic equipment due to voltage distortion problems
  - meets IEEE 519-1992 guidelines for voltage distortion at drive input terminals
• Meet rigid specification and construction requirements where harmonic mitigation is specified
  - meets IEEE 519-1992 guidelines for both voltage and current distortion at the controller input terminals
  - provides near unity True Power Factor
• Reduce installation cost with integral enclosure design