What is basic difference between Soft Starters And VFD
drives?

Answer Posted / ramamoorthy

VFD : VFD serves two purpose(smooth starting and speed
control):
a. Smooth starting by gradually increasing the source
power to rated output (by maintaining V/F ratio).
By starting at zero frequency & zero voltage (thus
the starting current also) and gradually increasing
the same to rated value.
b. Controls speed not only during starting but also at
rated voltage.

Soft starter serves only one purpose (Smooth
starting):

a. Smooth starting by gradually increasing the source
power only by increasing the voltage from zero
to full voltage and not varying the frequency like
autotransformer.
b. Cannot control speed at any point of time.

Is This Answer Correct ?    8 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

what is sevice settings for mccb?How can be it setted?

1472


What is a feedback in control system?

743


what is level 2 automation?

2704


what are the problems that generally occur in power flows??

2531


percetans

1699






how maney type tempereture measurement ?

1813


how we calculate the short circuit capacity of the busbar in LV & HT?

635


what is the working principle of energy saver control panel. please give the complete calculation & theory.

1821


what is model question rrb junior engineer electrical gr.II

1536


As we use capacitor bank in 3ph ckt to improve PF, can we use capacitor in single ph domestric use, in house we have Fan,Mixer,electric cooker,iron,tube choke they also lag the system,because it is inductive load. if it is possible to improve PF of single ph system-- if yes- type of capacitor to be used,connection diagram, working in detail. if no-- list it.

1266


why co incidence factor considered in transformer sizing?

1410


how to test and calculat the head and discharge in borewell compressor

1691


how we findout a ignater is faulty or not?

1582


What is the meaning of C1, C61, C91 cable

2811


If two Transformers are connected in parallel having impedance of 50KA in both transformers will the impedance increase or decrease after connecting transformers in parallel?

1529