Answer / srb

It is because as the resistance is added in rotor ckt,no doubt impedance increases due to which current decreases but the effect of improved pf predominanats the inc. impedance & hence torque inc. After some tym when motor has achieved considerable speed effect of inc impedance predominanats over improved pf & hence torque decreases.

Answer / nilkanth tailor

THEIR R BASICALLY TWO TYPES OF INDUCTION MOTOR
1) SLIP RING I.M.
2) SQUIRREL CAGE I.M.

GENERALLY, IN HIGH STRATING TORQUES MOTOR(DC SERIES
MOTOR) HAS HIGH STARTING CURRENT, AND ITS VERY DIFFICULT TO
CONTROL THAT CURRENT...BUT IN SLIP RING I.M THIER IS HIGH
TORQUES PRODUCE WITH LOWER STARTING CURRENT THAT IS MAIN
ADVATAGE...

THE MAIN DIFF BET. SLIP AND SQUIRREL CAGE I.M. IS THAT

1)The rotor of the slip ring motor has more windings than a
squirrel-cage rotor so that induction voltage is higher and
the current for the same field strength lower.
2)During start-up the a typical rotor has 3 poles connected
to the slip ring. Each pole is wired in series with a
variable power resistor.
3)During start-up the resistors reduce the field strength
in the stator. As a result the inrush current is reduced.

Answer / k.prakashchandra

The pf is improved

how to select cable size for three phase?

1 Answers  

---

Why using synchronising methed in DG's sets?

0 Answers   Juniper Networks,

---

why the protection turbo generators is most complex?

0 Answers   Infres, L&T,

---

I HAVE 2 nO'S OF SYSTEMS, HOW MUCH UPS CAPACITY REQUIRED ALONG WITH 400WATTS ANOTHER LOAD? PLEASE GIVE THE FORMULA?

1 Answers  

---

Hi i want to know that in generation station what we are generate either voltage or current

1 Answers  

---

---

Uses of induction motor

6 Answers   NTPC,

---

Ht panal kia hota ha?

1 Answers  

---

what is the diffrence between preventive maintinance corrective maintinance?

7 Answers   Siemens,

---

can we correct the p.f.of ac generator?

2 Answers   APGenco,

---

why voltage coil in wattmeter called as pressure coil why the pressure term is used in wattmeter?

1 Answers   NPCIL,

---

what is difference between di electric and insulator?

2 Answers   Greenko,

---

We have three 33kv substations. All of them energised by same source.When i am checking the phase sequence between one substation to other substation (like R Phase to R Phase) by multimeter i am getting some voltage.Near to LT panels UPS panels are there. Can u explain whether any possible to happen like that. In Phase SEquencemeter is showing correctly in both substations. How is it happen. Explain me.Explain me communication signal will produce Phase difference on this case.

3 Answers  

---