What are motor generator sets and explain the different ways the motor generator set can be used ?

0 Answers  

---

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.

0 Answers  

---

What is the basis for selecting Vk/2 or Vk/4 for REF and Differential protection of Transformer and What is the significance of magnetising current

0 Answers   ABB, Jindal,

---

How many types of losses occur in a transformer?

0 Answers  

---

how to calculate the multiplying factor for energy meter with CT ratio given

23 Answers   Bhel, Dalmia Group, DIFC, Fedco, Hindustan Unilever Limited, Lupin, MahaDiscom, MAL Pakistan, Myunghwa Automotive, Panchshil Infrastructure, Regala, RVPN, VIPL,

---

---

A thermistor is a type of

1 Answers  

---

what is the working of loss of excitation relay (40G)? how it is work?

1 Answers  

---

Does RCCB do the job of MCB? Lets take 16A RCCB. it trips when residual current exceeds 30mA. does it trip in an over current situation, i.e when current exceeds 16A ??

2 Answers  

---

a distribution transformer(3 phase)supplying 440volt per phase.now suppose one of phase voltage(230volt) becomes zero.what will be the cause ?

3 Answers  

---

why motor burns ?

5 Answers  

---

what is active power & reactive power?

0 Answers   Avtech, Jindal,

---

Is a direct shorth ciruit on a branch MCCB in a Low Voltage Switchboard a correct means of tesing the performance for discrimination?

0 Answers   Adani Power,

---