Answer / jeyapandian

always a motor takes starting current is hihg(5 or 6 times
full load current).
bcz,
I=V-E/r
at starting E=0,
so I=V/R
I is max.
at running , E has some value.so I decreses.

Answer / don

in squriell cage induction motor the rotor bars are short
circuted it cannot having additional resistance to maintain
the torque.thats why the induction motor takes 5 to 6 times
full load current. but slip ring induction motor we connect
rheostat (resistance) in starting it take normal current.

Answer / dharababu

IN MOTORS THE EQUATION FOR BACK EMF IS GIVEN BY
Eb=V-IR,
SO ARMATURE CURRENT I=V-E/R
AT THE TIME OF STARTING THE STATOR FLUX WHICH PRODUCES BY
SUPPLY,WILL NOT LINK WITH ROTOR AND THERE IS NO BACK EMF
PRODUCES IN ROTOR I.E I=V/R.

AS THE RESISTANCE OF ROTOR WILL BE VERY SMALL , THE
STARTING CURRENT WILL BE VERY HIGH .

Answer / ram

starting position is motor both through the (2.5-5)full
load current.in the motor starter is used in limit the
starting currnt. I=V-E/r

Answer / dipak sonkusare

Stator winding resistance is very less and emf induced at
starting (E) = 0. As V=IR so I=V-E/R... i.e. Ist is very
high.

After (10min) starting and during running, E increases
gradually which decreses the running current (Ir).

Hence starting current is always more more (5-6times) the
rated / running current of motor.

Answer / mohamed said

starting current is the ccrrent that the motor need to
satart = (2.5-7)Ir
running current is the current that the moto neede when it
loaded
ideal current is the rating current

what is value of Jin transformer

0 Answers  

what is the iron loss in a 11KV/440V transformer?

2 Answers   Bhel, TVS,

HOW TO FIND OUT 1. LINE CURRENT, 2. PHASE CURRENT IN AN ALTERNATOR / TRANSFORMER WHICH IS FEEDING A I)STAR LOAD ii) DELTA LOAD, USING A CLAMP METER. NORMALLY WHEN WE USE CLAMP METER IN A DG SET THEN WHAT DO WE GET?? PHASE CURRENT OR LINE CURRENT.

13 Answers   Bhel,

why shoud in High tension cable( above11KV etc.,)a semiconducting material coating will be there on insulation?

1 Answers  

What is core CT & it's function?

0 Answers  

what is rating providing of contactor,relay,fuse unit for motor output power

2 Answers  

how to set the transformer differential relay

1 Answers   Divis Laboratories,

Actually why the transformers ate rated in KVA.?

2 Answers   Torrent Pharma, XYZ,

Input power is 380 - 450 V but with 45 - 55 Hz frequency - desired output is 415 V and 50hz with 1% variation permissible. CVT / Servo dont stabilize the Frequency - what is best solution??

7 Answers   IOCL,

What will happen if an AC induction motor is applied with DC voltage?????????Kindly give all the posssible answers...

2 Answers  

How will u calculate wire size according to current rating?

2 Answers   Global Computer,

what is the difference between inverter and ups & what is the earth resistance for ups , if its high why so

3 Answers