The Optimal Solution for High Frequency Motor Protection

Flexsine® (60 - 120 Hz)

CTM Magnetics FlexSine sine wave filters are designed for optimal performance with both line frequency, 60 Hz, and 120 Hz motors. The FlexSine product line is engineered for today’s common 60 Hz induction motors with the built in capability of operating higher frequency permanent magnet motors. Buy for today, prepare for tomorrow.

  • Liquid-Cooling Technology
  • High Power Density
  • High Frequency

Product Options

  • Air Cooled
  • Liquid Cooled
Open-Chassis Options
  • Terminal Lead
  • Flying Leads
  • Liquid Cooled
Package Options
  • MagStand™ Cabinet
  • MagPallet™ Cabinet
  • MagPac™ VFD Integrated


VFD / Motor
VFD / Multiple Motors
Flexsine_ Motor
Flexsine_Multiple Motors

CTM vs. The Competition

CTM FlexSine®

  • Operates 0 – 120 Hz with no derate
  • No common mode noise
  • Highly reliable film capacitors
  • Integrated cooling system
  • Fully liquid cooled option
  • Military grade shock & vibrations

The Competition

  • High frequency derate required
  • Produces harmful common mode noise
  • Electrolytic capacitors
  • Inefficient silicon steel inductors
  • Cooling system not included
  • Air cooled only
  • Low shock & vibration capabilities


Product Highlights

Efficient Design

  • 120 Hz capability
  • No derate
  • Smallest size & optimized cost

Reliable Performance

  • Thermally protected capacitors & inductors
  • Highly efficient patented inductors & capacitors
  • No common mode noise

Plug & Play

  • Simple 3-in/3-out connection
  • No additional cooling required

Environmentally Rugged

  • Dust, wind, rain, weather proof (NEMA 3R)
  • -50 °c - +50 °c


The Optimal Solution for High Frequency Motor Protection

High Frequency 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. With the rise of high frequency/ high speed permanent magnet motors the need for higher frequency sine wave filtering has increased. CTM Magnetics FlexSine sine wave filters are designed to meet this rising need without requiring costly derates that negatively effect system size, efficiency, and cost.

Maximum Motor Lead Length:
Damaging voltage waves occur when motor lead lengths reach a characteristic length. These reflected voltage waves can cause damage to cable insulation and motors. By filtering the drive produced PWM waveform to a near perfect sine wave, CTM sine wave filters minimize harmful voltage, allowing for longer motor lead lengths (up to 15,000 feet in certain applications).

Stop Rewinding Motors:
Installing a CTM sine wave filter eliminates harmful voltage spikes, reducing insulation stress. CTM sine wave filters lessen harmonic current distortion, thereby minimizing unnecessary motor heating. By reducing winding stress and motor heat (two primary causes of motor winding failure), motor winding breakdown and failure is greatly reduced, minimizing the need to constantly rewind motors.

Extended System Life and Reliability:
CTM sine wave filters greatly reduce voltage stress and excess heat not just for the motor, but for all other load side components, greatly extending the life and reliability of the entire system.


FlexSine® Product Specs

Voltage Range
480 V ±10%

Fundamental Frequency
0 - 120 Hz
(Contact CTM for operating unit above 120 Hz)

Switching Frequency
3.0 kHz Minimum
2.0 kHz Minimum

Current Range
50 A - 1,500 A (Air Cooled)
50 A - 2,000 A (Liquid Cooled)

Enclosure Options
Open Chassis
NEMA 3R Cabinet

Motor Cable Length
Up to 15,000 feet

Agency Recognitions
cЯUus 1446 Standard
UL 508A

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.

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