Answer / nihar ranjan mandal

Amount of vacuum required to quench the arc at 132 KV level
will be very high. It is difficult to maintain that amount
of vacuum in practical purpose. Now a days we use GIS( gas
insulated substation for 132KV level. Where arc is quenched
in hydrogen chamber.

Answer / karunakar

Ionisation at higher voltages causes arcing between breaker
contacts hence deteoriation of contactors. This raises
another methods for arc quenching.. so for medium voltages
currents upto 3000A VCB's have longer life and better
operability.

Answer / deepak jha

Degree of Vacuum required for quenching of ARC at 132 kV
level system fault is very high and its very difficult to
maintain that much degree of Vacuum so don't use VCB in 132
kV level. we generally used SF6 for this purpose.

Answer / jobmonjacob

Vacuum restriction.

Answer / jobmon jacob

Factors contributing to interuptor selection are 1)voltage
2)metallurgy 3)vacuum 4)size 5)sc rating6)current chopping etc.

Answer / raghu

In 132kv and above switch gear required very high vacuum to quenching arc during making/breaking the contacts, now a days we r using gas insulated and sf6 switch gears for proper operation.

what is the purpose of taking HV test in LT panel.

1 Answers   PCE,

why transformers are rated in KVA

3 Answers   AITM,

what is the difference between linear choke and suction choke?

0 Answers   BARC,

how much the voltage & resistance should be ,between earth & neutral points.?& why?

6 Answers  

what is the operation of regulator in fan?

4 Answers   NTPC,

in transformer input is d.c signal which type of emf is induced

1 Answers  

low voltage distribution is done by a)3 phase 3 wire b)3 phase 4 wire c)single phase

3 Answers  

what are the compensations considered while designing a transmmision line.

1 Answers  

L.A. (Lightening Arrester) is located at a place from where transmission line enters the transmitting substation. So L.A. (Lightening Arrester) is the first equipments which has to encounter with lightening, high voltage surges and switching surges. It has to absorb energy of lightening, high voltage surges, and switching surges. L.A. (Lightening Arrester) is made up of layers of semiconductors. If these layers can not tolerate energy released by lightening, high voltage surges, and switching surges the L.A. (Lightening Arrester) blasts.

0 Answers  

What is derating?, Why it is necessary, it is same for all means for drives, motors,and cables.

1 Answers  

The corona effect is more in a) summer b) winter c) dry weather d) humidity weather

10 Answers   CPCL,

) why transformer cannot rotate though the principle behind induction motor is similar to a transformer

3 Answers