When and Why to Use Line choke or Input choke for ac drive / VFD

When and Why to Use Line choke or Input choke for  ac drive / VFD?  Line choke or input choke is nothing but like a transformer. Its basic function is to protect drive from surge voltage or over voltage spikes in the Mains input supply to VFD. Ac drive works on switching principle hence it produces harmonics and disturbs mains Line. Line choke helps in…

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When and why to use Dynamic Braking Resistor in VFD

When and why to use Dynamic Braking Resistor in VFD   Dynamic breaking resistor is used where motor connected to VFD which is generating regenerative energy due to high inertia or in case where deceleration time is so less that VFD cannot control motor to stop. Due to high inertia motor acts as a generator and starts producing energy. This energy is feed back to…

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VFD does not show display or Keypad is not Glowing/turning on.

VFD does not show display or Keypad is not Glowing/turning on. When you give supply to AC drives and display doesn’t turn on you can do the following process to troubleshoot VFD issues. It does matter which drive you have checking process is almost same. (allen Bradley, ABB, Danfoss, Delta, CG, Hitachi, Fuji or any other brand) Check Input Supply Voltage. Check whether you have…

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Over Voltage Fault / Alram

 VFD Trips on Overvoltage Fault? Ac drives shows overvoltage error My Drive Shows  This Fault AB ( Allen Bradley ) – Fault F3 ABB – Fault A2002 Danfoss – Fault 7 Delta – Fault ov Fuji- Fault OV1, OV2 and OV3 Hitachi – Fault 2, E07.3 and E07.4 Schneider – Altivar Fault ObF Siemens Fault F30002 Toshiba – Fault OP1, OP2 and OP3 When drive…

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Close loop and Open Loop Vector control Methods

What is vector control (closed loop vector) control?   Current s controlled with respect to Torque and flux components in vector control of VFD. This is achieved by VFD based on the rotor position, rotor speed and motor parameters. RPM and torque are controlled rather than output frequency. Relationship between voltage and frequency is decided by operating conditions. In Close loop Vector control generally Encoder…

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How much speed of a motor we can increase beyond rated speed with the help of VFD / Ac drive

How much speed of a motor we can increase beyond rated speed with the help of VFD / Ac drive   In certain applications we need to increase the speed of a motor beyond its rated speed in such cases before increasing the output hz of VFD you should consider few things.   Load Load on the shaft of motor should be considered. If load…

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Using Multiple motors on Single VFD

Selecting VFD (Variable frequency drive) or ac drive Multi motor applications There are few many applications where multiple motors are connected to a single VFD (variable frequency drive) or ac drive. We would like to highlight few things before you chose a VFD for such kind of applications. Overload Protection Full load current of all the motors connected Output choke Disconnect connection for each motor.…

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What is life of VFD / Ac drive

What Is Life of VFD? How much AC drive Last? What Is age of AC drives VFD?   There are many such questions peoples always keeps on asking.  Well some of the manufacturers gives working life of ac drives in there catalog ( Like 5 Years, 7 years or 10 years).Some Mentions Life of there components such as Life of dc Bus Capacitors, Life Cycle…

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