Product Overview

In 2006, CTM Magnetics produced the world’s first liquid cooled inductor. Since then, we have continued to improve upon this technology, redefining the limits of heat transfer in power electronics. Our RLL Reactors represent a culmination of nearly a decade of research and development in liquid cooled technology. Recent advancements have allowed for huge cost-optimization opportunities. With our RLL Liquid Cooled Line Reactors, for the first time, liquid cooled reactors are cheaper than their air cooled counterparts. RLL Liquid Cooled Line Reactors are a cost-optimized, high power density solution for preventing nuisance tripping and absorbing power grid disturbances that can damage variable frequency drives (VFDs) and other sensitive equipment. RLL Reactors provide an economical means to reduce downtime caused by unnecessary trips; protect equipment by absorbing voltage spikes and other transients; and reduce harmonic distortion. By leveraging superior heat removal technology, CTM was able to engineer an extremely economical, yet highly reliable product line.

Line Reactor Applications

  • Prevent Nuisance Tripping and eliminate 
expensive downtime
  • Protect Drive Electronics by absorbing 
voltage spikes
  • Reduce Harmonic Distortion and protect sensitive electronics

Liquid Cooled Advantages

  • Highest Power Density
  • Lowest Audible Noise with magnetostriction -
 free design and epoxy enclosed magnetics
  • Thermal Isolation from nearby electronics

Product Specs

Impedance Levels
3% and 5% (at 480 V)
Nominal Operating Voltage
480 V (208 - 690 V allowed)
Fundamental Frequency
50/60 Hz
Current Range
130 - 1,200 A
Overload Capability
150% rated current for 1 minute
Temperature Rise
100°C (180°F)
Maximum Coolant Temperature
45°C (113°F) (higher with de-rating)
Approved Coolants
Drinking Water Water-Glycol mixture For R134A, contact CTM
Cooling System Materials
Aluminum (standard)
Heat Removal
97% to Liquid Coolant
3% to Ambient Air
Maximum Altitude
No Limit

Superior Cooling Technology.
Highest Power Density.
Lowest Cost Solution.

CTM Line Reactors are the ideal filtering solution for practically any 6-pulse rectifier or inverter. Install 3% impedance reactors for absorption of AC power line voltage spikes and to reduce 90% of nuisance tripping. Use a 5% impedance reactor to protect against 99% of grid voltage spikes, and to protect the grid from drive induced harmonics and help you meet IEEE 519. The largest companies in the world rely on CTM technology, with more than 200,000 installed units in some of the harshest environments on the planet.

Line Reactor Applications

  • Drive Protection: CTM line reactors absorb voltage spikes, voltage transients, and other power line disturbances, extending the life of motor drive electronics, bridge capacitors, and semiconductors.
  • Minimize Nuisance Tripping: AC voltage spikes lead to rapid rises in the DC Bus voltage, causing the inverter to shut-off due to over-voltage. Line reactors absorb voltage spikes, significantly reducing nuisance tripping.
  • Reduce Harmonic Distortion: 6-pulse rectifiers are nonlinear loads that create significant harmonics; line reactors provide impedance to reduce harmonics, helping applications meet IEEE 519.
  • Protect Sensitive Equipment: Line reactors also provide protection for nearby equipment sensitive to harmonics distortion created by nonlinear loads.

Liquid Cooled Advantages

  • Highest Power Density: Superior heat removal provided by liquid cooling enables decreased overall product dimensions, yielding line-side filtering solutions with the highest power density available. Low surface temperatures mean typical component clearance requirements are virtually eliminated, thereby increasing “effective” power density further.
  • Thermal Isolation: With up to 97% of heat removed through the coolant, liquid cooled reactors have negligible effects on cabinet air temperature.
  • Extremely Low Audible Noise: Due to superior materials and geometric shapes, magnetostriction-induced noise is significantly lower in all CTM reactors. When combined with a epoxy-sealed liquid cooled package, the result is a nearly silent operation.
  • Cost-Optimized Solution: CTM has leveraged its liquid cooled technology to provide you with reliable and economical reactors for your line filtering needs.


Thermal Isolation

CTM liquid cooled reactors will have negligible temperature effects when installed in an existing cabinet. Liquid cooled inductors are thermally isolated from their enclosures, meaning a majority (97%) of the heat is removed directly through the liquid coolant.

In this example, both an air cooled and a liquid cooled reactor are sized for a 600 HP motor application; both reactors are identically 99.5% efficient (0.5% power loss). The air cooled reactor rejects 3,000 watts to the cabinet air, while the equivalent liquid cooled reactor only rejects 90 watts to the air. The remaining 2,910 watts are removed directly by the liquid coolant.

As can be seen in the graph, in a typical NEMA 3R cabinet, installation of an air cooled reactor will increase cabinet air temperature by 20.9°C . The equivalent liquid cooled reactor raises cabinet air temperature by only 1.4°C. The low temperature rise provided by liquid cooled reactors yields increased reliability for all electronics within the cabinet. Low surface temperatures also allow the liquid cooled reactor to smaller clearances, increasing effective power density further.

RLL Liquid Cooled Line Reactors

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