If a motor of 8.5 KW with same load and using in both Star
& Delta one by one,then which will take more current in
star connected or in delta connected

Answer Posted / subash nishad

take line voltage is VL and Zs is the impedence of
each phase,
then in case of delta connection ,VP=VL

phase current I(delta)= VL/Zs

we know that in delta connection ,
Line current IL= root 3 times phase
current
so line current I(delta)=root3*VL/Zs
in case of star connection,Vp= VL/root3
phase current I(star)= VL/root3*Zs
weknow that in star connection,
phase current=line current
IL(star)=VL/root3*Zs

so, IL(delta)/IL(star)= root3*VL VL
---------- / ----------
Zs root3*Zs


= root3 *VL root3*Zs
--------- * ----------
Zs VL

= 3

IL(delta) =3*IL(star)

hence, delta connection will take 3 times more current
than star connection..

Is This Answer Correct ?    9 Yes 0 No



Post New Answer       View All Answers


Please Help Members By Posting Answers For Below Questions

What will be the output voltage of a transformer if it is primarily energized from a square wave voltage source?

668


What is control system?

710


sir, iam a electrical engg graduate and i want to go in automation sector and for this i have decided to do industrial training for this,plz suggest me some good institute for the same in delhi,ncr. my degree percentage is 58%, can i get job after doing training, plz help....

1575


what is the effect of connecting three phase supply lines to three phase auto transformer output terminals through a fuse of 10Amp and a circuit breaker (MCB). Is this connection permanently destroy the transformer?

1465


1 “earthing” for bonding of equipment and circuits to common plant earth electrode potential, 2 “protective earthing (PE)” when this bonding is required for personal safety provisions 3 “grounding” for interference suppressing bonding of screens, sys-tems with ground level 4. low-impedance earthing ? 5.primary earthing system and secondary earthing system what is that? 6.earthing electrode or mesh net earthing electrode ? very confusing , simple but very informative help required ? i will be very very thankful to you guys.

1593






What is routh hurwitz stability criterion?

643


what is the eight bit unit?

1961


What is the need of generator relay panel

1515


Why it is possible to use PWM with a STATCOM and not with a conventional TCR based SVC

1567


Explain the advantages and disadvantages of hydropower plant?

658


The power supplied to a 50mH inductor from a 120V, 60Hz source will be

4202


A low wet bulb temperature indicates

689


pls tell me function of closing coil of A.C.B.

2883


How to convert a two phase power into a three phase power in induction machine?

1346


i have 90kw motor.so i choose connect cable .please what is parameter checked so please give to formula

1722