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.

Describe the function of Accumulator into the Pump

0 Answers  

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what's the minimum level required of SIL (safety integrity level)to use fire and gas system?

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Emergency Shutdown Systems/ Plant Shutdown System.

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Someone please do mail me some instrumentation questions for Hindustan Petroleum test to avinalexander@gmail.com .Really would be gateful if someone could help me

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State bernoulli’s application.

0 Answers  

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Explain the working principle of variable frequency drive?

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2 Answers   SCS,

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why level transmitter input is given 4to20ma

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what the pid setting in controller

2 Answers  

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Why we use 4 to 20 mA, (This is International Standard) instaed of this can we use 4-16, or 4-24 or 3- 15 or any other range

13 Answers   ONGC,

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