Golgappa.net | Golgappa.org | BagIndia.net | BodyIndia.Com | CabIndia.net | CarsBikes.net | CarsBikes.org | CashIndia.net | ConsumerIndia.net | CookingIndia.net | DataIndia.net | DealIndia.net | EmailIndia.net | FirstTablet.com | FirstTourist.com | ForsaleIndia.net | IndiaBody.Com | IndiaCab.net | IndiaCash.net | IndiaModel.net | KidForum.net | OfficeIndia.net | PaysIndia.com | RestaurantIndia.net | RestaurantsIndia.net | SaleForum.net | SellForum.net | SoldIndia.com | StarIndia.net | TomatoCab.com | TomatoCabs.com | TownIndia.com
Interested to Buy Any Domain ? << Click Here >> for more details...

why do we use star-delta starter. what is its need?

Answer Posted / d.ramesh classes

Technical explanation

When the windings of a 3-phase motor are connected in STAR:
the voltage applied to each winding is reduced to only (1 /.'/'3) [1 divided by root three] of the voltage applied to the winding when it is connected directly across two incoming power service lines in DELTA.

the current per winding is reduced to only (1 /.'/'3) [1 divided by root three] of the normal running current taken when it is connected in DELTA.

so, because of the Power Law V [in volts] x I [in amps] = P [in watts],

the total output power when the motor is connected in STAR is:

PS = [VL x (1/.'/'3)] x [ID x (1/.'/'3)] = PD x (1/3) [one third of the power in DELTA]

where:
VL is the line-to-line voltage of the incoming 3-phase power service
ID is the line current drawn in DELTA
PS is the total power the motor can produce when running in STAR
PD is the total power it can produce when running in DELTA.

by D.RAMESH CLASSES

Is This Answer Correct ?    19 Yes 8 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What is true sine wave or pure sine wave inverter?? Is it sine wave or step wave?? If it is step wave, waves with how much step is considered as pure sine wave? Is it possible to produce pure sinewave using power electronics?

1866


rajha power sector details

2017


Any one who apply for Ferro Scrap Nigam Limited cn join with me at rajuhalder@indiatimes.com or 09669717028

1968


what is the most permissible winding temp when we conducting a generator load test?(condition no load)

1711


Explain Energy and Power signals?

1759


Can RCD's used to protect the VVVF drive if not why.

2138


How do i carry out or know the vector group of a Dyn1 and Dyn5 transformer

2036


advantage of motor design on higher power factor . normally motors are designed for .8 power factor. what is advantage of designing at .88 power factor

1797


What is meant by time harmonics and space harmonics?

2792


Efficient electrical earthing in hard rock area

1558


What do you mean by ratio correction factor of instrument transformer?

1173


i am completed diploma in ece,and working in ht and lt lines.so is elligible diploma in ece for get electrical C Licence?plse give ur opinion?

1896


WE know that for Inductor X=2pifL,In DC f=0,then X=0 so,V=IX=0;But In the DC excitation of rotor of AC generator,DC motor field coil which coils are inductor so why does not applying DC voltage short the rotor coil of AC generator and field coil of motor?If it would then DC source might be damaged but it is not happened. Why does the strand conductor of Electrical power transmission line make twist?

4381


aternator every parts and its working

1625


sir pls tell me . our ct specifications are 120/5 ,2 core , 0.2 and 5p10 class , 30va and 30va buden. insted of 30 va i want use 15 va. can i use?

1505