Lightning Arresters or Surge Arresters are always connected
in Shunt to the equipment to be protected, they provide a
low impedance path for the surge current to the ground.
Wave trap is a parallel tuned inductor - capacitor 'tank'
circuit made to be resonant at the desired communication
It is the effort to utilize the same transmission line
between two substation for the purpose of communications.
At this communication frequencies the tank ckt provides
high impedance and does not allow to pass through them &
onto the substation bus & into transformers.
Lightening Arrester is connected in shunt with the lines so
that is protects from lightening.
when ever the lightening occurs, there is a voltage around
some thousands of voltage appear on line (3500V to 5000V)
for a fraction of seconds(25 to 30micro sec.s) which is more
than enough to damage all the equipment in the grid
connected to it. so when a lightening arrester is connected
then is provides low resistance path such that all that high
voltage is directed towards the earth resulting the
protection of all the equipments connected to the grid.
To protect human life and property, design engineers have to
install lightning protection systems on every GRID
SUB-STATION . The main function of the system is to capture
the lightning stroke, over voltage and then conduct
discharge current safely to the ground. Since there are 100
lightning discharges to the ground every throughout the
world, installing lightning protection systems are very
important for safety to human life and station
1. alternator has full load regulation of 4% when pf of the
load is 0.8 lag, 1500 rpm. full load regulation of 1400 rpm
for 0.8lag will be ________ ??
2. torque angle of a sync m/c operating from a constt
voltage bus is usually defined as space angle between _______ .
3. method most effective in finding out no load losses in
large DC shunt motoris ______ .
4. current carrying capacity of fuse material depends on
5. coil has res. 10 ohm, inductance 1H. what wil be current
after 0.1sec after switching on to a 500V DC SUPPL ? ?
6. effect of phase lag compensation on servo systems
7. rotor of a dc machine is usually supported upon ______ .
8. DC motor is preferred to AC motor in which application ??
9. 3 nos of 10:1 Xmer are connected in Star-Delta to supply
a load at 230V.the supply voltage must be ______ .
10. voltage source produces max current in which circuit.
11. cal. power, if current and voltage are out of phase by
12. suitable length of Xmission line of power at 66 KV.
13. Which of the theorm helps in simple computation when the
load across a ckt is varying ??
14. what is the adopted line length for power Xmission of
power by cables ??