Line Reactors (Choke)
 
line reactor

Line Chokes are modern technology solution for drive application. Protect your drive from harmful line disturbances with GR Line Reactor. GR reactors help to prevent equipment failure and down time and can add years to the life of your Drive.

Benefits:

  • Reduce nuisance over voltage tripping of drive due to transient voltage spikes and power line notches.
  • Improves input line current balance on Drive input when line voltage unbalance
  • Offer in-rush protection to input rectifiers caused by sudden power line surges sage.
  • Offer reduction of input line current harmonics by reducing the current form factor thereby improving power factor.
  • Reduce ripple current in the DC bus capacitor bank thus extending their life.
 
  Applications
line reactor
  • Power supply with high frequency transients such as voltage surges, line notching, pulsed distortion and harmonics
  • Drive supplied by a low impedance line. If the KVA rating of the Ac supply transformer is greater than ten times the input KVA rating of the drive, a 5% input line reactor must be added.
  • Power supply with phase unbalance greater than 2% of the voltage. An unbalance greater than 2% can shorten the life of drive and results in severe damage to drive power components.
  • Installation having more than two drives installed on the same power line. Multiple drives on a common power line require one reactor per drive to reduce cross talk.
 
  With Multiple Drives:
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Multiple drives on a common power line should have their own line chokes. Individual line chokes provide filtering between each drive to help reduce any cross talk while providing optimum surge protection for each drive.

 
  Selecting correct impedance rating:
Selecting the correct impedance rating is critical for your job. An impedance value too low may not limit peak current. Too high impedance may reduce input voltage. GR line reactors offer three impedance rating.
  • 1.5% impedance rectors are typically sufficient to absorb line spikes and motor current surges and will help prevent nuisance tripping of drive and circuit breakers in most application.
  • 3% impedance reactors protect against physical damage to most drive components and are best for absorbing line spikes and motor current surges.
  • 5% impedance reactors are best for reducing harmonic current and frequencies. These reactors help comply with IEEE-519 (not normally used as load reactors).
 
  Voltage spike protection:
line reactor

Voltage spikes on power lines can cause elevation of the DC bus voltage which may cause the drive to trip on an over voltage condition. 3% impedance reactors are very effective at protecting drives against voltage spikes and nuisance tripping. GR Line reactors absorb these line spikes protecting the drive from nuisance tripping.

 
  Design Features:
  Distributed Air Gap Technology:
line reactor

As reactors and their required air-gaps gets bigger, flux fringing and eddy currents can cause heating and insulation breakdown. GR has addressed this issue in larger. GR reactors by utilizing Distributed Gap technology - a construction technique that subdivides a large gap into two or more smaller gaps. A GR reactor built with this technique will run cooler and last longer than the competitions cheaper single gap products.

 
  PWM/IGBT Protection:
GR Reactors are specially designed and constructed for IGBT protection for drive application. A premium dielectric system is utilized to have a 3000V rms insulation dielectric strength required for IGBT application. GR Reactors are featured “triple insulation” suitable IGBT drives with switching frequency up to 20 KHz.
 
  K-Rated:
line reactor

A standard reactor is not designed for high harmonic currents and it will over heat and fail prematurely when connected to drive loads. For this reason a special reactor has been designed. This reactor is K-Rated reactor. These reactors are designed to have higher magnetic to resistive properties to handle heat generated harmonic currents.

High Reactor Linearity:

The linearity of GR Reactors is to offer 100% of their nominal inductance even at 150% of their current rating. This assures maximum filtering of distortion even in the presence of severe harmonics and absorption of surges.

 
  Installation:
Chokes are designed for mounting within appropriate electrical equipment enclosure. Chokes rated 80A and under are designed for mounting in both vertical and horizontal position. Larger chokes must be mounted on the floor of the enclosure. Maintain minimum clearance to all directions to ensure efficient ventilation.
The ventilation of the mounting area must be efficient enough to carry away the power losses generated by the Line Reactor. Allow side clearances of 100mm and vertical clearances of 150mm for proper heat dissipation and access.
The part of the enclosure containing Line Reactors must be forced ventilated according the dissipated power. Minimum Air flow must be: F= 0.3 X Ps in (Ps = power dissipated by the Line reactor)
 
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