Answer / vasu

VFD are used to make the motor to run in desired speed. By
variying the input supply frequency we can vary the speed of
the motor. some other types are VVFD - Variable voltage and
frequency drive, Vector drive.

Answer / rawjaw

We know a relation speed
say,N=120f/p,speed directly
proportional to freq.In some
applications large motors
used to drive a heavy load,we
start such motors from 0 rpm
& provides initial torque(say
160%) in order to achieve
energy efficient.ok..

Answer / hitesh kareliya

VFD Means Variable Frequency Drive,So that means we
controll the Pump's RPM via VFD in desired frequency.

Answer / amit shetkar

see firstly vfd is basically used mainly for 2 purpose i.e to
protect electrical motors & for speed control.
& now about that star delta arrangement it used before motor
in that star connection is used to give smooth start to motor
& when motor achieve it's speed so to maintain that speed
delta connection is used

Answer / vinay singh

When the elements are connected in neither series nor parallel
to reduce network star delta arrangement is used.

How a rtd work, and what volts/current goes to a RTD to measure the resistence?

1 Answers   DVC,

what is intrument termination what is commisioning

3 Answers  

How do you measure g's?

5 Answers   Aramco, GNFC, HPCL, Polmon, Thermax,

In which principles tx ,pressure gauge,Temp gauge,control valve works?

0 Answers   Bajaj, Professional Instruments,

Define the terms Accuracy, precission, Spam, process tolerance while doing calibration of an instrument? Explaini with an example?

0 Answers   AquaTech,

what is scale factor of proximitor & unit of the vibration.

0 Answers   ADMA OPCO,

Can anyone send most commonley asked Instrumentation questions and answers in cement industry please?

0 Answers  

What does PCU means with respect to Dead Weight Tester?

1 Answers   SGS,

how to derive kg/cm2 to mmwc? complete derivation.

11 Answers   L&T,

hello this is dhinakar i am completed my instrumentation engg . recently i got job in sugar industry side. i like to ask one question can any one say what are the things i have to follow know more about industrial instrumentation,,,,,,,

6 Answers  

If we increase only P what will be controller action ?

0 Answers   IMECO,

What is the use of each wire in three wire RTD

0 Answers   GSPC,