FlexSine® (60-120 Hz) Sine Wave Filters

One Filter. Induction and PM Motors. No De-rate.
CTM Magnetics, Harmonic Filters, Sine Wave Filters, liquid cooled, air cooled, high frequency, small footprint, harmonic distortion, power quality filters,
NEMA 3R Cabinet
Available in: MagStand | MagPallet | MagPac
Open Chassis:
Terminal Lead
Open Chassis:
Flying Lead

Product Overview

Buy for Today. Plan for Tomorrow. In addition to being a low cost 60 Hz sine wave filter, FlexSine®120 Hz sine wave filters can operate at fundamental frequencies up to 120 Hz without de-rating (Contact CTM for operating unit above 120 Hz). Motor advances are driving the market to switch to faster spinning PM motors. These higher speeds lead to high frequency harmonic distortion at the output of the drive. Consequently, our competitors’ filters overheat under this additional stress, forcing them to derate their filters. Furthermore, competitors often demand higher drive switching frequencies (to decrease THID), which then requires a drive derating.

However, there is another option. Due to a unique patented design and proprietary materials, FlexSine 120 Hz sine wave filters allow you to operate at 2.5 kHz (and up to 5 kHz) therefore avoiding any drive or filter derate. By installing a CTM FlexSine 120 filter now, you not only get the benefits of a low cost 60 Hz sine wave filter, you also unlock the ability to upgrade to a 120 Hz PM motor at no additional cost, whether that is an initial or future plan. Buy for today, prepare for tomorrow.

Patented Technology:

With patented liquid cooled technology, CTM sine wave filters offer the highest power density solutions available to the market. With a CTM liquid cooled product, 97% of the product’s heat is captured by the coolant and removed from the cabinet, protecting any heat sensitive electronics. Due to superior materials and geometric shapes, magnetostriction-induced noise is significantly lower in CTM filters. CTM products are quieter, “stealthier”, solutions for applications where noise is an important factor.

Custom Solutions:

For unique applications, CTM provides semi and fully custom solutions. The CTM engineering team will work with you to design a product that meets even the most challenging application requirements. Due to our design software, CTM is able to produce custom designs in as little as two business days. If you have any questions or need help finding a product give us a call today or submit a form through our contact us page.

CTM is the leading choice in power quality products because of our unparalleled capabilities. CTM offers the highest filtering capabilities, smallest package size, lowest noise, highest power density, no common mode noise, and competitive prices. Contact CTM today.

UL 508A LISTING AVAILABLE 

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Package Specs
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Harmonic Distortion

<5% THVD @ 2.5 kHz

Voltage Range

480 V ±10%

Fundamental Frequency

6 - 120 Hz (Contact CTM for operating unit above 120 Hz)
Switching Frequency

2.5 kHz Nominal | 2.0 kHz Minimum | (See FlexSine 120 Operating Range Chart)
Current Range

100 A - 1080 A (Air Cooled) | 100 A - 1,440 A (Liquid Cooled)
Overload Capability

150% rated current for 1 minute (Air Cooled) 200% rated current for 1 minute (Liquid Cooled)
Ambient Temperature Range

Maximum: 50 °C (122 °F) (Air Cooled) | 65 °C (149 °F) (Liquid Cooled) Minimum: -40 °C (-40 °F) (Air & Liquid Cooled)

Preventative measures should be taken to ensure the coolant does not freeze in the system.
Motor Cable Length

Up to 15,000 feet
Enclosure Options

Modular Panel | NEMA 3R Cabinet
Agency Recognitions

cЯUus 1446 Standard | UL 508A

FlexSine® 120 Highlights

  • Single Design for IM and PM Motor Operation: The FlexSine 120 is the only sine wave filter designed specifically for operation with today’s 60 Hz induction motor applications as well as tomorrow’s high frequency permanent magnet (PM) motors.
  • Avoid Equipment Derating At High Frequency: Competitors’ solution to high frequency PM motors is to force you to buy a larger filter and switch the VFD at 5 kHz. Not only are you forced to pay more for the larger filter, the 5 kHz switching frequency derates the drive, increasing up-front costs further by requiring a larger drive. The FlexSine 120 is different. Due to a unique patented design and proprietary materials, the FlexSine 120 allows you operate at 2.5 kHz, avoiding any drive derate. The FlexSine 120 also is rated at full current up to 120 Hz (Contact CTM for operating unit above 120 Hz).
  • Upgrade to PMM with Existing Equipment: The FlexSine 120 allows you to use your current drive to upgrade to PMM frequencies. Simply switch out your existing sine wave filter with an appropriately sized FlexSine filter to start reaping the benefits of PMM.

Sine Wave Filter Advantages

  • Motor Protection: Harmful square waves, voltage spikes, and harmonic distortion are all filtered from the inverter output, reducing motor heating, wear, and winding stress, providing critical motor protection.
  • Maximum Motor Lead Length: Reflected voltage waves occur when motor lead lengths reach or exceed a characteristic length of the system, which is dependent on the voltage rise times (dV/dt) in the cabling. By filtering the PWM waveform to a near perfect sinusoidal waveform, CTM sine wave filters minimize dV/dt, allowing for longer motor lead lengths (up to 15,000 feet in certain applications).
  • Electric Fluting (Bearing Current): Common-mode (bearing) current can have disastrous effects on induction motors, leading to electric fluting and premature bearing failure. CTM offers sine wave filters that do not introduce common-mode currents.
  • Low Audible Noise: Due to superior materials and geometric shapes, magnetostriction-induced noise is significantly lower in CTM filters.
  • Integrated Thermal Management: CTM FlexSine filters are outfitted with fans for thermal management and low operating temperature. Coupled with a liquid cooled option, CTM’s patented liquid cooled technology traps and removes 97% of the filter’s heat in the highest power density solution available to the market.

Cost to Upgrade to 120 Hz

Following our competitor recommendations, upgrading to 120 Hz can be a costly endeavor, with filter de-rates of at least 25% and drive de-rates of at least 20% (due to the recommended 5 kHz switching frequency). These recommendations become even more costly with field retrofits, as the drive and filter are essentially scrapped.

However, there is another option. By installing a CTM FlexSine 120 filter now, you not only get the benefits of a low cost 60 Hz sine wave filter, you also unlock the ability to upgrade to a 120 Hz PM motor at no additional cost, whether that is an initial or future plan. Buy for today, be prepared for tomorrow.

FlexSine® 120 Operating Range

The FlexSine 120 product line is electrically designed to provide -17 dB attenuation at a switching frequency of 2.5 kHz. The product line is thermally designed to operate at 120 Hz and minimum 2 kHz switching frequency. The chart to the right displays the frequency ranges for all CTM sine wave filter products.

With an operating switching frequency of 2.0 kHz the attenuation drops to -12.4 dB and allows for more harmonic distortion at the output of the filter. It is up to the customer to determine if this is an appropriate amount of filtering for the application.

Harmonic Distortion

<5% THVD @ 2.5 kHz

Voltage Range

480 V ±10%

Fundamental Frequency

6 - 120 Hz (Contact CTM for operating unit above 120 Hz)
Switching Frequency

2.5 kHz Nominal | 2.0 kHz Minimum | (See FlexSine 120 Operating Range Chart)
Current Range

100 A - 1080 A (Air Cooled) | 100 A - 1,440 A (Liquid Cooled)
Overload Capability

150% rated current for 1 minute (Air Cooled) 200% rated current for 1 minute (Liquid Cooled)
Ambient Temperature Range

Maximum: 50 °C (122 °F) (Air Cooled) | 65 °C (149 °F) (Liquid Cooled) Minimum: -40 °C (-40 °F) (Air & Liquid Cooled)

Preventative measures should be taken to ensure the coolant does not freeze in the system.
Motor Cable Length

Up to 15,000 feet
Enclosure Options

Modular Panel | NEMA 3R Cabinet
Agency Recognitions

cЯUus 1446 Standard | UL 508A

FlexSine® 120 Highlights

  • Single Design for IM and PM Motor Operation: The FlexSine 120 is the only sine wave filter designed specifically for operation with today’s 60 Hz induction motor applications as well as tomorrow’s high frequency permanent magnet (PM) motors.
  • Avoid Equipment Derating At High Frequency: Competitors’ solution to high frequency PM motors is to force you to buy a larger filter and switch the VFD at 5 kHz. Not only are you forced to pay more for the larger filter, the 5 kHz switching frequency derates the drive, increasing up-front costs further by requiring a larger drive. The FlexSine 120 is different. Due to a unique patented design and proprietary materials, the FlexSine 120 allows you operate at 2.5 kHz, avoiding any drive derate. The FlexSine 120 also is rated at full current up to 120 Hz (Contact CTM for operating unit above 120 Hz).
  • Upgrade to PMM with Existing Equipment: The FlexSine 120 allows you to use your current drive to upgrade to PMM frequencies. Simply switch out your existing sine wave filter with an appropriately sized FlexSine filter to start reaping the benefits of PMM.

Sine Wave Filter Advantages

  • Motor Protection: Harmful square waves, voltage spikes, and harmonic distortion are all filtered from the inverter output, reducing motor heating, wear, and winding stress, providing critical motor protection.
  • Maximum Motor Lead Length: Reflected voltage waves occur when motor lead lengths reach or exceed a characteristic length of the system, which is dependent on the voltage rise times (dV/dt) in the cabling. By filtering the PWM waveform to a near perfect sinusoidal waveform, CTM sine wave filters minimize dV/dt, allowing for longer motor lead lengths (up to 15,000 feet in certain applications).
  • Electric Fluting (Bearing Current): Common-mode (bearing) current can have disastrous effects on induction motors, leading to electric fluting and premature bearing failure. CTM offers sine wave filters that do not introduce common-mode currents.
  • Low Audible Noise: Due to superior materials and geometric shapes, magnetostriction-induced noise is significantly lower in CTM filters.
  • Integrated Thermal Management: CTM FlexSine filters are outfitted with fans for thermal management and low operating temperature. Coupled with a liquid cooled option, CTM’s patented liquid cooled technology traps and removes 97% of the filter’s heat in the highest power density solution available to the market.

Cost to Upgrade to 120 Hz

Following our competitor recommendations, upgrading to 120 Hz can be a costly endeavor, with filter de-rates of at least 25% and drive de-rates of at least 20% (due to the recommended 5 kHz switching frequency). These recommendations become even more costly with field retrofits, as the drive and filter are essentially scrapped.

However, there is another option. By installing a CTM FlexSine 120 filter now, you not only get the benefits of a low cost 60 Hz sine wave filter, you also unlock the ability to upgrade to a 120 Hz PM motor at no additional cost, whether that is an initial or future plan. Buy for today, be prepared for tomorrow.

FlexSine® 120 Operating Range

The FlexSine 120 product line is electrically designed to provide -17 dB attenuation at a switching frequency of 2.5 kHz. The product line is thermally designed to operate at 120 Hz and minimum 2 kHz switching frequency. The chart to the right displays the frequency ranges for all CTM sine wave filter products.

With an operating switching frequency of 2.0 kHz the attenuation drops to -12.4 dB and allows for more harmonic distortion at the output of the filter. It is up to the customer to determine if this is an appropriate amount of filtering for the application.

FlexSine® (60-120 Hz) Sine Wave Filters
Download Brochure
FlexSine® (60-120 Hz) Sine Wave Filters
Download Brochure
FlexSine® (60-120 Hz) Sine Wave Filters
Download Brochure

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