tan delta equation test on alternators

2169

working principle of oil startar

1849

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.

1977

How many double suspension hardware fittings are required on a double circuit transmission tower?

1885

please send me previous year questions of jspl through which i could prepare myself for the test.

1845

Hello to all, Please someone can send me HPCL ELECTRICAL Engg. Sample papers to me? Its urjent....my email address is.... raviasiapacific@gmail.com

2096

what is die electric strnth of transformer ?

2137

how to calculate the fault in substation

2367

The efficiency of a 100kva transformer is 0.98 at full load as well as half load , for this transformer what is the Copper loss at full load ?

2287

How to see the inductance in a transmission lines

2101

In our plant we have installed new MCC with ELR and CBCT which is detecting some leakage current in the system but it leading to some confusion when to check that in which feeder which is drawing current we put off the whole panel itself but still CBCT detecting some leakage current so can anybody ans me , where i am going wrong or how to detect whether its actual leakage or CBCT malfunctioning.

2221

my b-tech percentage is 50%. what answer will satisfy the hr ?

2060

what is the pulse and audio frequency transformer? what is different between induction regulators and tap changing transformer?

2071

salam,hi, i need to know what the spesification of 300amp msb...

1993

What is line resistance of cable & how it can be measured ?

1456