Controlling the electricity flow to a motor has several benefits, prominent ones being saving electricity and preventing the damage that may occur due to a large inrush of current. For the purpose, we have two devices or equipment viz. soft starter and VFD (Variable-frequency Drive). Knowing more about them will help you understand the differences, and which one to choose.
A soft starter in your soft starter panels uses multiple (typically 6) thyristors or rectifiers which include parts like cathode, anode and a logic gate. The model can prevent larger than normal inrushed of current (as in the case when the internal pulses do not apply to the gate). Therefore the actual voltage that reaches to a motor is limited and the current is slowed. But here, the motor will work at its topmost speed, as the current is at its upper threshold and limit, while not being excessive.
VFD (Variable Frequency Drive)
The VFD consists of filter, inverter, and rectifier. The rectifier changes the incoming AC electric current to DC or direct current. The filters contain the capacitors for smoothening the current, while the transistors of the inverter change the DC voltage to AC sine form and send it to the motor. VFDs also have the ramp-up and down feature to control the outflow of the current to the motors.
Also Read: What are the Advantages of Using a Variable Frequency Drive
Which One to Prefer: Soft Starter or VFD
While the VFDs may be priced higher than the soft starters, they provide great savings and offer immense returns on investment. Here is why VFDs can be a better option.
Energy Efficiency: use of VFD for starting motors and other equipment and appliances provides for an energy savings of up to 70%.
Control: VFD can ramp up and down the current-voltage. A soft starter will only reduce the large current inrushes.
Size: VFDs have a larger size than the soft starters.
Also Read: VFD Retrofit Options and Benefits for Units and Plants
In most cases and scenarios, VFDs turn to be a better option. We have the best VFD suppliers and manufacturers present and selling online nowadays. Consult them free of cost and know more about the VFD benefits for your industrial processes.