Answer Posted / j.senthamizh

First we should be convert ac into dc using rectifier. Dc
motor speed control method classified into two 1.armature
control 2.field control . we are using armature control
method motor speed can be control below rated speed.or
using field control method the motor speed is above rated
speed. most people using armature control method because
field control method is dangerous than armature control
method.we are using field speed control at motor is running
condition and now field is open which times motor running at
dangerous speed. at the time motor bearing and shaft is
affected this condition.

How to calculate the Harmonics losses in terms of cost/unit.

1964

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In synchronous motor, how the field current is related to armature current..i know its inversely proportional..but concept wise...i was nt clear....pls help me...

1974

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Haw to check conductivity of budbar

1753

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What are factors to be considered while we selecting the Core Balance Current Transformer for Earth fault protection

1819

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Hello Guys !! i want to rrb section engineer electrical(signal) previous model papers? any body help me?

1847

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Is vtg is controlled by the resistor? if else how much?

2039

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how we decide scurt (disc) of insulator with respect to kv rating

3486

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how to find the resistance and gap volatage of the diode??

1986

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What is meant by earthhing of a magnetic flow meter and when to use empty pipe detection?

2179

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What are your future plans for the company if permanently employed?

2111

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Draw the DOL starter and star delta starter drawing?

2937

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What is the purpose of stand by earth fault protection for transformer ?

2023

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What is excitation in case of dc motor?

1109

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Is there any standard guidelines/Criteria to design NGR/NGT.?

2788

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delta motor winding resistance I take normally single winding is 2.5, which value is came delta connection ie RY ?

1942

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