Answer / gobind

Whan the generator have synchronized with grid the waveform
have 120 Deg each phase but at the time of any fault
occurred in the grid system,at that time the waveform of the
grid voltage have been reduced from 120 Deg to min at that
time vector Shift Relay have operated.Permissible limit of
the vector Shift 8 Deg.

Answer / ajay vikson

Hi,

here is a useful link on the vector surge relay

http://www.electrotechnik.net/2009/04/vector-surge-relay.html

Answer / k.p.sharma

We have the vector surge relay setting at 12 deg. But i observe that at that setting many time tg breaker tripped with grid breaker as per scheme only grid breaker trip is required. Please tell me is this setting ok or not.



K.P.Sharma

My switchgear busbar is rated at 2000A and just imagine the actual load on busbar is 1000A. From that busbar there are 10 outgoing feeders. Now the question is will the load be 1000A on each outgoing feeder or 100A per outgoing feeder. 2nd thing how do i calculate the load on individual feeder. Thanks for your time. Please provide some clarification on this issue.

1 Answers   Alstom,

---

For 7.5kw star delta starter how to calculate 1. Mccb rating 2. Contactor rating 3. Over load relay rating

1 Answers   L&T, MAHINDRA,

---

This is urgent!! What is a Thyristor-based 3-ways selector switch with Zero crossing control? how does it operate and where is it mostly found in a system?

0 Answers  

---

why does chattering take place in ac contactors? can it be avoided & what care does the manufacturer take to eliminate this phenomenon????

10 Answers  

---

in a induction motor if we put capacitor across it will the power factor of the motor will improve? if yes how

6 Answers   Reliance,

---

Frequency of rotor emf in induction motor is around A same as stator frequency B 50% C 5 % or below D 30%

1 Answers   Bhel,

---

There are 2 Flip_Flop with logic between them. Given Clock to Q delay, logic prop. delay, set up and hold times specify maximum clock frequency of system. What happens if second output fed back to first input. Any changes? What happens with timing if second output is fed back to logic between the flops? Good Luck!

1 Answers   Qualcomm,

---

what is the switching substation

2 Answers  

---

what is the merz prodution ? what is the turn to turn fault?

2 Answers   L&T,

---

Why reverse power relay is used?

12 Answers  

---

why we setting 95 deg and 105 deg in wti and oti of distibution transformer ? give the reson for that ?

0 Answers  

---

I have 30KW Motor Starter Panel, System voltage is 480V, So i have to convert voltage 480 to 220V to give the contactor coil. How i can select control transformer, Which rating transformer i can use this panel, what is the procedure, please tell me.

2 Answers  

---