Answer Posted / kapil kumar

Earth is a safety point and neutral is a protactive point
for equipment

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]

2285

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What are the reasons for the parallel operation of transformers?

1077

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redundant connection in contactor?

2439

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What are the components connected in between the power supply coming from an electric pole to HT & LT Panels in a large commercial building or how the power supply connected from Electric pole to Transformer & then to the HT & LT panels of a building? Please send me answers via mail, my id is yogiagarwal@gmail.com. If possible, please give a line diagram.

2019

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Is Transol transformer oil comparable to nynas nytro libra?

3058

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When are the directional relays used?

1001

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What is diversity factor in electric installations?

1120

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the grid connection required for a 50 MegaWatt fotovoltaic powerplant is higher or lower than 35kv (high or medium tension)?

1803

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Difference between HRG and NGR. Are they both the same thing

4224

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what is the carona effects meaning in HT line transmmission system

1939

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WHY DO VOLTAGE TRANSFORMERS FAIL DURING EARTH FAULT IN THE DELTA CONNECTED 6.6KV ELECTRICAL SYSTEM

1937

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on a three-winding transformer relationship delta-delta-star, on third winding why the relationship is a star? what are the advantages and disadvantages? Thank you and please help

1689

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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.

1962

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What should be the protection scheme for a 15kw, 3-phase motor working in a lathe machine.

2016

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how to calculate current carring capacity of cable and cable selection? 1) copper flexible cable 2) copper armoured cable 3) Aluminium cable

1545

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