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Servo Drive & Motor Expert | VFD AC Drive Repair

Posted on 19th Oct 2023

Requirements for Power Supply in a Variable Frequency Drive

keb f5 drive

According to CM Industry Supply Automation - Servo Drive & Servo Motor Expert, "We get our electricity from the high-voltage national grid and its low-voltage subsidiaries, which are fueled by wind turbines, turbo-alternators, and other similar sources that number in the tens of thousands". Because these rotating machines have significant inertias, industrial power utilities are typically sturdy by nature, referred to as "stiff," and are generally regarded as able to start and stop heavy loads on a regular basis without experiencing any problems.

Public power supply networks can serve large loads at startup with very little voltage fluctuation since they are typically low-impedance.

Rural environments

Longer overhead electricity lines may be required in rural areas in order to access certain isolated localities. These longer connections raise the power supply's source impedance, which increases the installation's susceptibility to voltage dips, sags, and surges. When constructing a VFD installation in such settings, the ramifications of such must be considered.

Installations with higher power

The likelihood of a possible short circuit current at the variable frequency drive input terminals under fault conditions in higher power installations needs to be taken into account. These fault currents can harm a lot of equipment and can reach hundreds of amps in less than a millisecond. The VFD power supply can be equipped with additional impedance, such as that offered by ordinary line reactors, to slow down the rate at which these fault currents build. This will provide circuit protection devices more time to function and remove these faults before harm is done.

Vital power supply factors to consider

It is necessary to verify that the power supply voltage and frequency are compatible before choosing a motor and variable frequency drive. Before choosing equipment, it is important to identify any potential large voltage changes from the specifications provided by the VFD and motor manufacturers. These manufacturers should then be consulted.

For the entire VFD system, the cable cross-sectional area and type must be properly selected, and all protection and switching devices must work with the electrical load and installation.

Their user manuals will include the precise power supply voltage, phase number, and frequency in addition to the VFD-rated input and output current, allowing for the selection of the right cable sizes and protection devices.

key conclusions

    A crucial factor to take into account is the power supply, which needs to be more powerful than the driving mechanism.
    Prior to making a purchase, make sure the VFD and the motor instructions are compatible.
    For high power installations or installations in remote locations, for instance, you might need to take additional precautions to guard against supply-related mishaps such voltage fluctuations and short circuits.

CM Industry Supply Automation - Servo Drive & Servo Motor Expert is available to provide professional guidance.

CM Industry Supply Automation - Servo Drive & Servo Motor Expert  provides superior inverter drives and top-notch support to electrical contractors and end customers of all sizes about their drive systems.

We provide premium variable speed drives that will enable you to optimize application performance, add automated control features, and increase project energy efficiency.

Speak with one of our variable frequency drive such as Lenze Drive, Keb F5, Keb F5 Drive, Siemens Drive & more.