HG7 HarmonicGuard Filters: Performance Improvement from Proven Technology

Trans-Coil, Inc.’s HG7 HarmonicGuard drive-applied filters provide the solution for facilities where variable-frequency drives (VFDs) or other nonlinear-load devices represent a significant portion of the load, or when specifications call for limited harmonics. When applied at the drive, the HG7 provides a low-impedance path for the major harmonic currents demanded. This solution greatly reduces the amount of harmonic current flowing through the distribution system, resulting in improved power factor, lower RMS currents, lower harmonic-current and harmonic-voltage distortion, and increased system capacity.

As power utilities are pushed to the limits of supply capability, power consumers must confront the issues of rising energy costs and decreasing power quality. To address these issues, users install more variable-frequency drives, UPS systems, and other nonlinear loads.

Devices that draw non-sinusoidal current from the distribution line cause nonlinear loads. This non-sinusoidal current derives from waveforms that combine the fundamental frequency with integral multiples of that frequency, resulting in harmonic distortion. If these loads represent a significant portion of an electrical system, harmonic distortion may propagate throughout the entire system, causing problems that can include poor power factor, overheating of transformer and distribution equipment, random breaker-tripping, or even sensitive-equipment failure. Since harmonics affect the overall power-distribution system, power utilities levy heavy fines on facilities that affect the utilities’ ability to supply power to all of their customers efficiently.

The HG7 not only limits current distortion to less than 7% TDD (total demand distortion—typical results are 5%–6% TDD), it also improves true power factor. Since every power system is different, harmonic-mitigation requirements differ; even IEEE limits change based on system-loading characteristics. Users may select from several package options, ensuring that they have the correct filter for a given application. The HG7 series returns the power of choice to the user, allowing for different configurations to achieve different performance and monitoring results.

The HG7 series is available in 240-V, 480-V, and 600-V designs in standard 7.5–900 Hp (100 Hp maximum at 240 V). All come with a three-year manufacturer’s warranty. Options include the standard package, the power-monitor package, and the component package.

Standard Package

The standard package includes everything necessary for an application to meet IEEE 519 standards and is perfect for applications where floor space is at a premium. From the highest-quality harmonic-grade capacitors on the market to extraordinary reactors, this filter will meet the majority of application requirements found today. This cost-effective product is available as either an open-panel version or in a UL Type 1 enclosure. The open panel is perfect for inclusion in a motor controller section or industry-standard enclosure. The UL Type 1 enclosed units maintain the same vertical profile as the open-panel version.

Power-Monitor Package

The power-monitor package includes contactors and filter-monitoring equipment. This package uses indicator lights for filter operation and fuse failure for units rated at 60 Hp and below. For units rated from 75 Hp–350 HP, the power-monitor package uses the HG2 protection-monitor/harmonic-power factor meter. The HG2 monitor board displays operating information such as ITHD, VTHD, total filter amps, true power factor, and a series of fault and protection codes including overcurrent, overvoltage, and phase imbalance. The HG2 monitor board is also a programmable safety monitor, capable of bringing the filter offline in a fault condition, or when the drive goes into a fault condition. For those applications that require the removal of capacitance for the startup of standby generators, the contactors can remove the harmonic-duty capacitors. Above 400 Hp, the power-monitor package includes a monitor board with indicator lights to advise the mode of operation and when a fault should occur.

 Component Package

This package includes all of the major components that are found in the standard package. Ideal for integration into drive sections or other end products, this option is intended for the experienced drive integrator. The component package does not include panels, enclosures, heating or cooling devices, wire, or lugs. The inclusions of the power-monitor package are not available in the component package.

The HG7 is not only guaranteed to perform, its performance matches all but the most expensive mitigation technologies currently available. The HG7 is easy to install and is shipped with all necessary components. Each unit contains high-quality capacitors certified for harmonic-rich environments. The HG7 is designed so that critical applications will continue to operate even if the filter itself shuts down. Contact the sales engineers at McNaughton-McKay to discuss how Trans-Coil, Inc.’s HG7 HarmonicGuard drive-applied filters can benefit your facility.