Answer Posted / v.balakrishnan,shj

Circuit breaker is used to break the power supply from
loads like switch, but it also protects loads from over
current, short circuit and earth fault.
Types of Circuit breakers as follows:-
MV
1.Air Circuit Breaker (ACB)
2.Vaccum Circuit Breaker (VCB)
3.Oil Circuit Breaker
4.SF6 Circuit Breaker
LV
1.Air Circuit Breaker (ACB)
2.Moulded Case Circuit Breaker (MCCB)
3.Earth Leakage Circuit Breaker (ELCB)
4.Miniature Circuit Breaker (MCB)
5.Motor Protection Circuit Breaker (MPCB)

(by,V.Balakrishnan,Shj,050-8847343)

Is it required to lay 2 runs of GI wires along with armoured cables from one power DB Machines of higher rating?

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ii) A shunt motor supplied at 230V, runs at 900 rpm when the current is 30A. The resistance of the armature is 0.4 ohms. Calculate the resistance required in series with the armature to reduce the speed to 600 rpm, assuming that the armature current is then 20A. [12]

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Q.1:What protection will be used on HT and LT side of 33/0.4 KV, MVA transformer. Indicate capacities of protective device to be used. Q.2:Which types of back-up protections are used in the power transformers? What do you understand by the term over travel in the relay? Q.3:How star and delta connected winding transformer are provided from earth fault

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I HAVE A 50A MCCB AS PER DESIGN LINE WIRE CONNECT UPWORD SIDE AND LOAD IS CONNECTED TO DOWNWARD SIDE TO THE MCCB.IF NOW ANY ONE CHANGE SUPPLY & LOAD(WISEVERSA) WHAT HAPPENS ? DOES MCCB OPERATION OR WORKING FUNCTION NORMAL IF YES THAN WHY THERE ARE MARKED LINE & LOAD ON MCCB.

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Define peak overshoot.

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Keywords: Die, Card, Coin, B/N 2 To 12

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