Answer / rakesh patel

Formula: K=
R.V/1.73R.A
where R.V=Rotor
voltage ,
R.A=Rotor
Current ,
K=constant ,
than
1step=1.40K ,
2step=.35K ,
3step=.15K ,
4step=.08K now
put the data and
get your ans.

Answer / purushottam

This motor is used for both purpose as it is used in 15 Ton
EOT crane main Hoisting / Lowering application. External
resistance used for speed control & for High Starting Torque
both.

Answer / p.veerapandian

Can u tell the application of the inserting external
resistance in the rotor circuit for speed variation or
starting with heavy torque application

Answer / prashant

All hoist and travel drives in EOT cranes, or any equipment for that matter, that use Slip Ring Induction Motors and need speed variation use these resistance boxes. The method of calculating steps in external resistance is absolutely correct as told in 1st answer.

Answer / gulzar ahmad naikoo

There is thumb Rule for percentage of cutting resistance.1st step full calculated resistance,2nd 50% of total,3rd,50% of 2nd,4rh 50% of 3rd, and so on.

Answer / prakash gidde

Mr. Rakesh, Pl explain how many % of external resistance need to cut en each step during operation of slip sing motor? also pl explain on which bases u considered 1.4, 0.35, 0.15 & .08 value for calculation of step wise resistance.
cutting of resistance should be on application of motor where to we are going to use & lifting load capacity. Also its depend on which type of resistance we are using -- SS punch plate grid / punch wire grid/ oil merge/ liquid water resistance.

why in isolation transformer we dont get any shok?

2 Answers  

is 3-phase induction motor need a starter ? why do it so

5 Answers   Coca Cola,

What is the main difference between generator and alternator

4 Answers  

How to calculate ant test the burden of Current transformer

0 Answers   NTPC,

1. how much normal earth resistance in earth pits(neutral and body earth) and transformer neutral and body earth & panel earth.

12 Answers   HP, Malladi Drugs and Pharmaceuticals, Pearl Engineering, PL,

what is high voltage in india?

11 Answers   Essar,

why transmition and distribution and genaration of voltage in multible of 11 means 220v,440v,11kv,22kv,,,...so on

3 Answers  

What are approaches to tackle sedimentation problem of reservoir?

0 Answers  

what maximum range of star & delta in hp or kw ?

0 Answers   Makkah Hilton Towers,

what would happen when synchronous motor will operate beyond syncronous speed?

3 Answers  

How I can Compare 120v/60Hz versus 220v/50Hz ? Please tell me both advantage and disadvantage ......

0 Answers  

What is the formulae of Megger value for a A.C.Motor

0 Answers