why is used for starters for staring motors?
Answer Posted / priya
Starters are used to limit high currents during starting by adding resistors in series with armature circuit which are excluded gradually when the motor speed increases. High starting currents are due to
1. In case of DC motor, initially back emf(E) is zero therefore I=(V-E)/Ra becomes V/Ra. Generally Ra armature circuit resistance is very low hence I is very high during starting. When speed increases back emf increases and I reduces therefore resistors can be excluded.
2. In synchronous motors starters are not used
| Is This Answer Correct ? | 6 Yes | 0 No |
Post New Answer View All Answers
In HI POT test what is reason for applying the AC VOLTS and DC VOLTS in different applications what is the nessesity for this ?
why we have and use 3 phase not 2 or 4 or other in power system?
how external lighting design? please give examples?
how many current required for hypo test
How much minimum insulation required between 11kv/3.3kv transformer windings?
How test for Ddo vector group test condition?
What will happen if i used 11KV earth ht kit to 11 KV / 11 KV cable termination?
How should i design a 1ph & 3 ph transformer. Kindly let meknow all steps and formulaes related to design from scratch.
Define coil span?
What is the feedback in the control system?
How is operate breaker failure scheme in substation
At the starting of dc motor and syn.motor and induction motor high current flowing through the winding. Due to this the windings burnt out. To avoid this different types of starters are used. But incase of transformer what Will be used (At starting no emf is induced in the primary winding)?
how we can find of current direction(supply comming/out going direction) when a transmission line passing through sides.
hi frds, i m electrical engineer.can i get cdr for electrical engineer if u have then send me on my mail id its jayesh_ee88@yahoo.com.please help me frds
in ring main system we use the isolater b/w transfer bus and main bus if we r not use isolatar than wat will be the effect in our sys.