Product Overview

IEEE-519 Compliance.

Partial Load Performance.

On-board intelligence.

Non-linear loads such as variable frequency drives (VFDs) increase efficiency; however, they significantly pollute the power quality of the site and grid by introducing substantial harmonic current distortion (THD-i). The addition of a CTM GridDefender Passive Harmonic Filter reduces harmonic current distortion below 5%, ensuring compliance with IEEE-519 and protecting other on-site equipment. Furthermore, GridDefender filters perform well under partial load conditions, are generator compatible, and do not require drive control of capacitor contactors (simply customer connections).

Product Specs

Typical Applications
Six-Pulse Rectifier (generator compatible)
Input Voltage / Frequency
480 V / 60 Hz
Current Range
240 - 640 A
Maximum THD-i
<5% @ Full Load
<8% @ 25% Load
Overload Capability
150% rated current for 1 minute
Maximum Ambient Temperature
50 °C (122 °F)
(higher with de-rating)
Enclosure Options
Modular Panel
NEMA 3R Cabinet
Capacitor Contactors
Contactor for capacitor disconnect with automatic pickup and drop out (no drive connections required for control)

GridDefender Highlights

  • Meets IEEE-519: VFDs introduce harmonic current distortion on the grid that can cause
    problems for nearby equipment. The addition of a GridDefender filter
    reduces current distortion below 5% THD-i, meeting IEEE-519
    requirements and eliminating nuisance tripping of the drive, nearby
    equipment, and circuit breakers.
  • Simple Customer Connections (3 In / 3 Out): Control for capacitor contactors is maintained within the filter, with
    automatic pickup and dropout. This feature greatly simplifies field
    installation, only requiring three input and three output power
    connections (temperature monitoring optional). Less connections
    minimizes the chance of improper installation, which has caused
    performance issues and failures in competitor filters.
  • Excellent Partial Load Performance: GridDefender Harmonic Filters not only meet IEEE-519 requirements
    under full load conditions, they also are designed for partial load
    performance, with THD-i levels maintained below 8% all the way down
    to 25% load.

GridDefender Harmonic Filters

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