Answer / rahul faye

A variable-frequency drive (VVVFD) is a system for controlling the rotational speed of an alternating current (AC) electric motor by controlling the frequency of the electrical power supplied to the motor. A variable frequency drive is a specific type of adjustable-speed drive. Variable-frequency drives are also known as adjustable-frequency drives (AFD), variable-speed drives (VSD), AC drives or inverter drives

Answer / saravananp

In Electrical:- VFD(Variable Frequency Drive). This is used to monitoring and controlling the speed of the driven based on the variation of frequency.

In Mechanical:- This is used to control the flow of air within the duct in terms of CFM(Cubic foot Metre).

Why the steam turbines are run at high speed where as the hydro turbines are run at low speed?

1 Answers  

---

How do i perform grounding of star point of Genset (400V) for making connection with step up transformer of DELTA-DELTA (400V to 20KV) ? while Genset itself has its own neutral and grounding bus bar inside genset breaker box whereas we have another neutral and grounding busbar in synchronizing panel next to genset at maximum distance of 6meter, would someone pls advice if we can only perform neutral grounding in synchronizing panel or should we ground neutral on both places inside genset breaker box and synchronizing panel.

0 Answers   Allied Group,

---

can we use breather in a SEALED power or distribution transfomer instead of injecting nitrogen.

1 Answers  

---

What aturn on methods of scr?

0 Answers  

---

difference between a four point starter and three point starter

9 Answers  

---

In a 3 pin plug holder, what is the purpose of diameter of ground pin is larger than phase and nutral pin

9 Answers   Coal India, HCL,

---

How do you calculate of power factor, if it is lagging or leading for unit(1).

4 Answers  

---

what should we do when the CT secodary gets open? how do we short circuit it? using tester or screw driver? not dangerous?

6 Answers  

---

how to select the double earth conductor if 21A full load?

0 Answers   L&T,

---

why high voltage is reqiured or L.T. panels? what type of tests should be taken for electrical panels?

2 Answers  

---

How to distinguish whether MCB is DC or AC looking at it physically

0 Answers  

---

Fantio of tranformer

0 Answers   Tenon,

---