Answer / gennadiy

Yes, the voltage in the simpliest V/f control is decreased proportionally with the speed decreasing. V~f in linear V/f control and V~f*f in parabolic V/f control (for pumps and fans).

Answer / h s sandhu

VFD means variable frequecy drive,If voltage is reduced then speed will reduce.

Answer / devinder

No effect on motor speed.
N=120F/p

Answer / uditparashar

ifbthe motor is running in constant torque mode then decreasing the voltage will result in increase in frequency hence speed will increase in constant torque mode otherwise speed will decrease

How the setting of the vector surge relay shall be calculated when the relay is to be used for Grid islanding application?

0 Answers  

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how kva rating of transformer is calculated.

6 Answers   Fluor Daniel, Siemens,

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draw waveform of capacitor or inductor in a d.c ckt(during transient) with zero resistance with it(in series or parallel)also neglect resistance of wire

2 Answers   L&T,

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Write the current equation in series RLC circuits.

0 Answers   Agilent, Integreon, ZS Associates,

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what is meant by motor protection relay & its working principle ?k

1 Answers   Pricol,

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what is effect of unbalaced load -- say R 15A, Y 25A, B 10A

4 Answers   TransWorks,

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1. If we apply dc supply to the primary winding of transformer it will be burnt out. similarly dc supply is given to field winding of syn. motor and armature winding of dc motor, they are safe. (Remember both windings inductive nature) what is the reason behind that?

2 Answers  

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You required 5A from the transformer but you get 8A. How do you minimize this?

2 Answers   Bajaj, Siemens,

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differnce between single acting and double acting solenoid valves

0 Answers  

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what is difference between low voltage and high voltage

3 Answers  

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using in R,Y& B PHASE LTSIDE(415V)ct ratio 4000/5 WITH ENERGYMETR OF 1280 REV./KWH,240V.WHAT WILL BE MF OF METRE.

1 Answers   HCC,

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what is ten delta test? what is the significanse of it

1 Answers  

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