Answer / Savitri

No, a 4-pole RCCB (Residual Current Circuit Breaker) requires a complete three-phase circuit with both the neutral and earth connections to function properly. The residual current is calculated as the difference between the sum of phase currents and the neutral current. Without the neutral connection, the RCCB cannot detect faults or tripping conditions.

why do we connect voltmeter in parallel,why not in series,and why do we connect ammeter in series why not in paprallel...

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any body,pls tell me how to done relay coordination ? how to coordinate by TCC curve?how to read the tcc curve?

1 Answers  

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Comparative difference between 33Kv & 66KV for transmitting the load of 7 MW at a distance of 34 Km.

6 Answers   NHPC,

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a solar energy installation utilizes a three phase bridge converter to feed energy into power system through a transformer of 400v/400v.the energy is collected in a bank of 400v battery and is connected to converter through a large filter choke of resistance 10ohms.1.the maximum current through the battrey will be.2.the kva rating of the input transformer is.

1 Answers   GATE,

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why the perameters of secondary circuit are more important then that of the primary circuit of induction motor?

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Why we use 4-20 mA Analog signal for the PLC input? Why not 0-20 mA? Why not 5-25 mA?

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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,

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We have 800KW motor operating at 6600Volt,50 Hz supply.During 1st startup it tripped on overcurrent trip.It's FLA is 88 Amps.The K factor of Thermal overloaaad was set on .94 initially.then we set at 0.97 and then it started fine.i dont understand why it tripped first?What are the protections which comes in picture during starting ?

6 Answers  

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What should the transformer connection of a 11/220 kV step up and 66/11 kV step down transformer ?

4 Answers   CGL,

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In a 3 phase 4-wire system. For a 3.5 core cable if all loads are single phase and balanced, what will be neutral current? will it be sum of all phase currents? Or it will be zero? And if loads are unbalanced what will be neutral current?

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how motor should be connected i.e star-delta or star-star or delta-delta ?

3 Answers   GSE,

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if u want to buy a motor than what will be the configuration of that motor?

2 Answers  

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