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CoolTube®

At MH&W, we offer CoolTube® as the definitive solution for mitigating radiated EMI in VFD motor systems. Designed to act as a high-performance choke, CoolTube® absorbs damaging high-frequency noise before it can reach your equipment, preventing premature bearing failure and unscheduled downtime. Whether in industrial HVAC or automotive applications, our nanocrystalline technology ensures maximum system reliability and reduced maintenance costs by tackling interference at its source.
CoolTube Selection Tool
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Shielded Cable Replacement

CoolTube® Radiated Emission Chokes allow for the use of standard unshielded motor cabling, significantly reducing total costs. This switch simplifies cable routing and makes the physical installation process much easier for technicians.

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Superior EMI Mitigation

These nanocrystalline chokes effectively absorb high-frequency noise between 5 MHz and 1 GHz. They provide better suppression than traditional ferrites while utilizing only 20% of the magnetic mass.
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Maintenance-Free

Designed for long-term reliability, these components require zero maintenance throughout their entire operational life. This “fit and forget” solution ensures your system remains protected without the need for periodic inspections.
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Application Versatility

CoolTube® chokes are extremely versatile and suited for demanding sectors like HVAC, automotive, and renewable energy. Their performance remains stable across a wide variety of industrial motor applications.
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Simple Installation

The chokes are designed for seamless integration and work effortlessly with standard unshielded cables. This eliminates the complex grounding requirements of shielded alternatives, leading to faster assembly times.
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Scalable Size Options

Available in five distinct sizes, CoolTUBE ensures a precise fit for a wide range of motor applications. This scalability allows engineers to choose the most space-efficient option for their specific power levels.

Nanocrystalline Technology

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Base Material: The core is primarily composed of iron (Fe), which provides the foundation for its magnetic properties and contributes to its high saturation flux density, allowing it to handle strong magnetic fields.

Key Additives: Specific elements like silicon (Si), niobium (Nb), copper (Cu), and boron (B) are added in precise proportions. These additions play crucial roles in refining the microstructure and enhancing the material’s soft magnetic characteristics.

Microstructure: This microstructure is achieved through a specialized manufacturing process involving rapid solidification and controlled heat treatment, resulting in superior magnetic performance.

Resulting Properties: The nanocrystalline structure yields desirable magnetic properties: high permeability for efficient flux conduction, low coercivity for minimal energy loss, low core losses for improved efficiency, and high saturation flux density for handling high power.

Part # Power (HP) CoolTUBE® per Cable Length (Feet) Documentation Purchase
1-150 151-300 301-450 451-900*
CT17X135 HP1/4-10A8 1/4 - 10 1234 Datasheet Shop Now
CT35X240 HP11-40A14 11 - 40 1234 Datasheet Shop Now
CT54X360 HP41-100A18 41 - 100 1234 Datasheet Shop Now
CT195X415 HP101-428A40 101 - 428 1234 Datasheet Shop Now
CT240X473 HP429-1600A50 429 - 1600 1234 Datasheet Shop Now

Frequently Asked Questions

What is CoolTube® Radiated Emissions Choke?
In the given configuration CoolTUBE® soft magnetic cores work as a single turn common mode suppression choke. They do not affect the symmetrical power currents but efficiently dampen the asymmetrical radio frequency noise currents.
Nanocrystalline absorbers are superior to other soft magnetic materials like ferrites because of significant advantages concerning their magnetic properties. Therefore, only about 20% of magnetic mass is required – i.e. a significantly reduced number of cores is suitable.
Electromagnetic Interference, simply known as EMI, is a disturbance in the radio frequency spectrum that affects fields even if their frequencies are not aligned. This is because electromagnetic radiation can still interfere with each other even if they are not on the same frequency, and this is exacerbated by the fact that devices emitting electromagnetic waves tend to also transmit at lower power on harmonic side bands, which is why an FM radio might pick up powerful signals from a nearby CB radio.

EMI is a problem on electronic devices since electronic circuits are very susceptible to it because electromagnetic radiation can easily be picked up by any conductor. Therefore, speakers sometimes make noise when a nearby cell phone is receiving a call or text message. This is because the coil in the speakers is acting like an antenna which captures the EMI emitted by the cell phone.

EMI can be a serious problem in critical systems that use radios. An airplane, for example, requires electronic devices to be turned off during takeoff and landing, as they might cause interference with communication between the pilot and ground control or other critical systems being used by the plane.
No. CoolTUBE® cores installed with suggested guidelines absorb the emissions below levels specified by EMI test labs and other governmental agencies. At this level, the emissions are no longer dangerous enough to emit and cause disruption in the system.

All electronic devices (telephones, computers, microwave ovens, HVAC equipment, pumps, etc.), including VFD’s, motors, and even shielded cables are thoroughly tested and confirmed in EMC labs to prevent the devices from affecting the power grid. They are tested to meet standards. The problem with VFD motors and systems is they are not tested together because of the numerous configurations in the field. We in North America see VFD bearing damage and system level devices because North America does not have a strict level of EMI standards for VFD related systems.

All electrical devices create emissions/radiations that will interfere with the external environment. These emissions have the potential to interfere with the electrical grid and other local electrical devices.

There are two main types of electrical emissions: Conducted emissions and radiated emissions.
No maintenance is required on the cores. Once installed, they last a lifetime, and can even be left on the system if a new motor or drive is installed.
Not necessarily. Electrical fluting and frosting occurs when conducted emissions, in the form of high frequency current, is passed through the motor bearing. Conducted emissions are in the range 200kHz, to approximately 5MHz. These currents cause EDM. Radiated emissions start at approximately 5MHz and go up to several gigahertz. These radiated emissions are not connected to anything in the system, rather they are emitted into the air. The affects can be noticed in communication devices such as radios, telephones, and of course if left unprotected, communication links, sensors, and other VFD system related devices.

At MH&W, our CoolTUBE® solution provides a revolutionary defense against radiated EMI by absorbing high-frequency noise before it can damage your VFD motor system. By acting as a high-performance nanocrystalline choke, CoolTUBE® ensures maximum equipment longevity and prevents costly unscheduled downtime across industrial, HVAC, and automotive applications.

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