Answer / u.v.v.satyanarayana

dol is a direct on line starter means less than 5h.p
machines consists of roughed construction so resistance is
high.so there is no use of starting current limiting.
but in case of high rating motors starters
necessaty.

Answer / anandh

The motor will draw a high starting current until it has run up to full speed. This starting current is commonly around six times the full load current.To reduce the inrush current, larger motors will have reduced-voltage starters or variable speed drives in order to minimise voltage dips to the power supply.

DOL starters uses upto 5 HP motors.Star/Delta starters uses at above 5 HP motors.

DOL starter starts the motor in directly at on line.But Star delta starter starts the motor at directly and works at star and after 5 sec works at delta .

What is the principle of residual protection?

0 Answers  

---

hi frnds...pls send me aptransco previous papers .....pls..pls,,,(madhar.rocking@gmail.com)and suggest me some websites

0 Answers  

---

what is the use of neutral displacement relay

1 Answers   OCL,

---

What is the distance between body earthing and neutral earthing.?

1 Answers  

---

Slip at maximum torque depends on A rotor resistance and reactance B stator reactance C load current D stator resistance

1 Answers  

---

Explain RLC circuit?

0 Answers  

---

how to setting Load amps tripping time and extra settings for load Transformer protection relay with RMU panel using C&S model relay..?

0 Answers  

---

two parallel conductors are carrying the current in the same direction.which of the following statements is true? (a)there is arepelling force between the conductors (b)the force increases when the distance between the conductors is increased (c)there is an attaracting force between the conductors (d)the force increases when the distance between the conductors is decreased

1 Answers  

---

1.what type of wave is produced from i.online ups ii.offline ups iii.inverter.why don't we use inverter instant of offline ups for computer,what's the reason?

2 Answers  

---

To generate electricity , what is the speed of rotor?

1 Answers   JEC,

---

Can motor act as generator (OR) vice versa? explain how does it do please post the answer technically

11 Answers   GM General Motors,

---

what is meant by phase &line voltage, how its differ from each other ?

5 Answers  

---