Answer / sumit

in absence of 3 phase supply no rotating magneic field will
produce . . .. . .

Answer / kj

A 3 phase supply is the lowest number of phases where a
rotating field is produced. No extra starting controls are
needed (e.g. capacitor start or start windings)
Two phase systems have been used and can produce a rotating
field but it has to use a setup with separate neutrals for
each of the 2 phase. It therefore requires 4 wires to each
motor instead of 3 and it is also not as efficient.
Three phases also has the advantage of the currents in the
nuetral not being the sum of the 3 phase currents. In that
way only a single neutral can be used as the return for any
single phase load on all the 3 phases.

Answer / t lakshmi narayana

Why because two phase supply cannot work.Let us consider 2
phase a,b.If a=0 then b=180 electrical degrees apart. Both
are out of phase i.e net torque is equal to zero.
Electrical degree = 360/phases.
In 2 phase it is 180
In 3 phase it is 120 which gives a torque.

Answer / wareagle

Because it does not exist.

i completed my DEEE. and i want to electrical c license. how to get it..?

0 Answers  

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How the CT and PT ratings are calculated

5 Answers  

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Why a starter is used for a motor?

50 Answers   L&T, Nilachal Polytechnic,

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why the carbon brushes are broken in srim while the motor runningtime

0 Answers  

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how do find power factor in practically and what it means?

3 Answers  

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Hello everyone, somebody knows what is a "surplice power" ? The hole phrase is: "This rating is appropriate for a generator set paralleled with an infinite bus e.g. a national electrical supply network or grid where the generator set is run at 100% load, 24 hours a day, 365 days a year and any surplice power is exported into the grid" Thanks in advance.

0 Answers  

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how does a liquid starter reduce the starting currents?

0 Answers  

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What device is use for metering current at lt consumer end..??

2 Answers   Power Grid,

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we all know that in transformer, voltage and current are inversely related i.e. Vp/Vs= Is/Ip....so in standard CT..we have a ratio of 200/5...that means our voltage should increase by ratio of 40..althoug that is not the case...because that requires high insulation level.and pratically not feasible......can anybody clarify my ques.......thanx

2 Answers  

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what will happen when square wave is fed into input side of 3kva transformer and what you will get on output side.

3 Answers   Blue Star,

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Can someone explain how does an IDMT relay works.

1 Answers   AFM,

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What are the difference between CT/PT operated Meter and RRAMR Meter for HT/LT application?

1 Answers  

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