Why dc Supply used in Control circuit.

Answer Posted / vishal

In control ckt ,tripping ckt plays very imp role. Let us consider circuit breaker when fault occurs our relay gives trip command which lasts for fraction of second since AC has zero crossing probably DC is used & which is reliable...!

Is This Answer Correct ?    2 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

An 8 pole, 50 Hz, 3-phase IM is loaded to a poing where pull out torque will occur. The rotor resistance per phase is 0.3 ohm and motor stalls at 650 rpm. The rotor reactance at stand still is A 2 ohm B 1.25 ohm C 3.15 ohm D 2.25 ohm

1767


How to calculate per unit impedance of transformer?

1579


How to calculate the value of earth capacitance in a transmission line.

1806


state the working principle of incondenscent tube?

1541


Explain how you can give the overload setting to any Motor Protection Relay for a HT motors with formula and example?

1663






Please tell me in DETAIL about the following 3 types of fuses or recommend me a good power system protection book or a website link ? 1.Dropout Fuse 2.Striker Fuse 3.Empulsive fuse (not sure if its impulsive or explosion fuse , sorry)

1682


how to calculate slip ring induction motor stator and rotor currents??

1751


how to calculate sizing of NGTR (Transformer rating,Loading resistor value and Current rating of resistor) and what is the X/R ratio. Details : 11kV,Capacitance 1.73532 micro farads,40kA for 1sec.

1747


Comment on the working principle of operation of a single-phase transformer.

716


I want formula to calculate current loss with distance in km.I searched many sites but didn't right answer.Plz reply me

1573


diff b/w normal grounding and resistance grounding

1428


what is kondo syatem in eletrical traction

1676


How can i get my certificate of competency as an electrical supervisor? I have complicated my B.Tech from Uttarakhand technical university this year (2012).

4005


what are the major & minor faults that occur in an inverter and in UPS ? And how to repair and resolve them ?

1844


How can find thermal state value in relay for calculate thermal overload.

1430