Answer Posted / vipul

soft stater working in 2 contectter in use by stating
current in soft stater load in full rpm in dol contecter

1. A 380 / 220 V r.m.s. 3-phase 4-wire circuit carries loads of 8 + j8.1 ohm; 4 + j4.1 ohm; and 2 +j2.1 ohmin the three phases respectively. The length of the circuit is 100 m, and the resistivity of the phase conductors is 0.0005 Ω/m. The neutral conductor is of the same size as the phase conductors. a) Select a reference angle 0for the first phase. Then write down the three phase voltages in both polar format and complex number format. b) Make appropriate assumptions, and take temperature effects on resistance is insignificant. Calculate the currents in the three phases. (Note: Determine conductor resistance, and apply Kirchhoff’s Voltage Law) Based on the result, suggest a main switch rating for the circuit. c) Show your preferred direction of neutral current in a diagram, and then determine its value. (Note: Apply superposition principle, and Kirchhoff’s Current Law) Use its magnitude to show that in this circuit, the unbalanced load may increase the voltage drop in some of the phases. (Note: Also observe the common volt drip in neutral) State your assumptions, if there are any. d) Suddenly the neutral wire of the circuit is broken. Estimate the new currents in the first phase, i.e. Phase L1. State your assumptions, if there are any.

2034

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can anybody send me syllabus of rrb section engg (electrical). and also send previous question pepar...

1985

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WHAT IS THE USE OF PIG TAIL IN WINDOW CT ?

2537

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for opening electrical shop, tips needed.

1828

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What is the permissible limit of shaft voltage for 6.6 KV motors ? Why? Is there any standard is available?

2658

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1) Explain why we don't link the two earthing system ht and mv on a pole mounted transformer sub-station.

1789

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what are the necessary basic electrical topics to learn for mechanical engineer to deal practical problems.

2229

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WHAT IS THE SIGNIFICANCE OF VECTOR GROUPS IN TRANSFORMER? WHAT WILL BE EFFECT WHEN PHASE DISPLACEMENT CHANGES IN TRANSFORMER?WHAT IS THE NEED TO BE PHASE SHIFT CHANGE BETWEEN THE PRIMARY AND SECONDARY WINDING

1787

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During FEED, you will have all the information with regards to cable. How will you calculate the MTO for MV and LV Cables? what are your considerations?

2470

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If there is major % of Voltage harmonics in the system, how can it be control or reduced?

1989

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

2226

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Does outdoor isolator loose connection cause short circuit current in that circuit? if yes then how ??

1700

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give single line diagram of D.G distribution form alternator to main L.T panel?

7560

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what purose of the double circuit transmission line phase of the line phase changed for circuit-1 for Circuit-2 R-Y-B B-Y-R

2286

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Draw transformer phasor diagram.(full load,no load)

4177

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