Answer / rakesh ranjan sharma

It is the process by which the reversed polarity of residual magnetism can be corrected by using an external dc source to remagnetise the field poles in correct direction.........

Answer / monika

In alternators it is necessary to have some resudual
voltage to buildup an voltage. The residual voltages
weakens because of ageing & keeping at rest condition for
long time. In this cases using external DC sourses will
applied to field terminals to create residual. This process
is called as field flashing.

Answer / k.prakashchandra

Static exciter uses thyristors for converting AC to
DC .Thyristers require a minimum voltage to conduct,for
which the voltage created by residual magnetism is not
sufficient.To bring the generator volage to the required
value ,field flashing is done with dc source or AC through
rectifier.Once the required voltage is built up,the
generator output will take over the excitation with field
flashing off

Answer / kumar

I can't clear about this question but in alternator we
flash the field in RR(rotating rectifier)by give the Dc
voltage directly to field Its the method for developing AC
voltage

can you send me the placement papers of electrical engg. from companis like NTPC,DRDO,IOCL,HPCL,BPCL etc.?If,plz send as soon as possible.Thanks.

0 Answers   NTPC,

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How do you think they do earthing or grounding in ships and aeroplanes?

9 Answers  

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Why do we mix soda with water in LRS?

1 Answers  

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why field resistance is higher than armature resistance in dc machines? and why filed resistance is kept at min value at starting in same time of armature resistance at max value?

4 Answers  

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what is the type of motor that is used in emu units in india

1 Answers  

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what is the difference between the voltage of 5 volts capacitor and and 5volts battery?

0 Answers  

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what is the technical diffrences of mccb and acb

11 Answers   TransWorks,

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Why we use circular(Stepped) cross section in transformer core?

0 Answers  

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what is the difference between H.T Or HV lines...?

1 Answers  

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USE OF 8 WAY PAN ASSEMBLY

0 Answers   TCS,

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when the size of the cable used for the ht voltage is 300sqmm then what is the size of the conductor of each phase

2 Answers  

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WE are using a 63A MCCB(SIEMENS MAKE) for one of the feeder in LV substation panel.It is supplying to a lighting & power socket DB.Settings in the MCCB is Ir = 63 * 1 , Isd = 8 times of Ir , tsd = 0.5 sec( I2 t off). Sometimes this MCCB is tripping .But no trip in DB MCB. Can anybody tell me reason ? From where i can know about the MCCB settings?

5 Answers  

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