The Necessary Accessory for Your Motor and VFD

Posted on 13th Dec 2023

Darwin Motion Drive

The necessary accessories for a motor and Variable Frequency Drive (VFD) setup depend on the specific requirements and application of the motor drive system. Darwin Motion - VFD & Servo Drive manufacturer share some common accessories and considerations:

Motor Protection Devices:

Overload Protection: Overload relays or electronic overload protection devices safeguard the motor from excessive current, helping prevent overheating and damage.

Thermal Protection: Temperature sensors or switches monitor the motor's temperature, ensuring it stays within safe operating limits.

Phase Protection: Devices that protect the motor against single-phasing or phase imbalance issues.


NEMA Enclosures: Ensure that the motor and VFD are housed in appropriate NEMA-rated enclosures, protecting them from environmental factors like dust, moisture, and corrosive substances.

Filters and Reactors:

Line Reactors: Help reduce harmonic distortion and protect the VFD from voltage spikes.
EMI/RFI Filters: Mitigate electromagnetic interference and radio-frequency interference, which can affect the performance of sensitive equipment.

Braking Systems:

Dynamic Braking Resistors: Used with regenerative VFDs to dissipate excess energy when decelerating the motor.

Communication Devices:

Communication Modules: Enable communication between the VFD and control systems, allowing for remote monitoring and control.

Fieldbus Modules: For integration with industrial communication protocols like Profibus, Modbus, or Ethernet.

Cables and Wiring:

Shielded Cables: Protect against electromagnetic interference and maintain signal integrity.
Proper Sizing: Ensure that cables are appropriately sized for the motor and VFD to minimize voltage drop and power losses.

Remote Keypads and Human Machine Interface (HMI):

Keypads: Allow for local control and programming of the VFD.
HMI Displays: Provide a user-friendly interface for monitoring and adjusting parameters.

Bypass Contactor (for HVAC applications):

Bypass Contactor: Enables the motor to run directly on the power line when the VFD is bypassed, simplifying maintenance and troubleshooting.

Isolation Transformers:

Isolation Transformers: Provide electrical isolation and protect the motor from voltage spikes and disturbances in the power supply.

Ventilation and Cooling:

Cooling Fans: Ensure proper ventilation and cooling for both the motor and VFD to prevent overheating.

Input and Output Reactors:

Input Reactors: Reduce the impact of power line transients on the VFD.
Output Reactors: Help protect the motor by smoothing the output waveform and reducing motor heating.

It's important to consult the motor and VFD manufacturers' such as Darwin Motion that provide Micro Drive- Matrix 900, DR Matrix 350 / Solar Drive, High Frequency Drive - DR Matrix 500, High Performance Drive - DR Matrix 680, Regenerative Drive - DR Matrix 880 guidelines and specifications to determine the specific accessories required for your application. Additionally, compliance with local electrical codes and regulations is crucial for a safe and reliable motor and VFD installation.