How to select circuit breakers rating eg. if i select a circuit breakers of capacity 40 amps DC with operating voltage 28 volts and if i what to use same circuit breakers for 300 Volts DC application what is the current rating of this circuit breakers.

0 Answers  

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Why the size of transformer decreases if we increases the frequency?

5 Answers   Graphics Engineering,

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why we not using 230kv directly why we are stepping down and then stepping up

2 Answers   Siemens,

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Grid fault level [KA]?

0 Answers  

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why active power is called as real power or working component.What is the exact function of active, reactive & apperent power.

3 Answers  

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what's float charger and boost charger? why it's used?

2 Answers   APCPDCL, PTCL, Rolls Royce, Siemens,

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in india,we use 230V,50 Hz,whereas many other countries use 110V,60Hz.what r d advs and disadvantages of each of them?

11 Answers  

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What are the advantages of skewing of cage rotor conductors?

0 Answers  

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1. What is the difference between ac induction motor and ac synchronous motor?

11 Answers  

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why a three phase induction motor cannot run at synchronous speed ?

7 Answers   RUET,

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We have 800KW motor operating at 6600Volt,50 Hz supply.During 1st startup it tripped on overcurrent trip.It's FLA is 88 Amps.The K factor of Thermal overloaaad was set on .94 initially.then we set at 0.97 and then it started fine.i dont understand why it tripped first?What are the protections which comes in picture during starting ?

6 Answers  

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what is power factor? whether it should be high or low? why?

11 Answers  

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