Answer / rohit

Core balance CT (CBCT): The CBCT, also known as a zero sequence CT, is used for earth leakage and earth fault protection. In the CBCT, the three core cable or three single cores of a three phase system pass through the inner diameter of the CT. When the system is fault free, no current flows in the secondary of the CBCT. When there is an earth fault, the residual current (zero phase sequence current) of the system flows through the secondary of the CBCT and this operates the relay. In order to design the CBCT, the inner diameter of the CT, the relay type, the relay setting and the primary operating current need to be furnished.

Moving Iron instruments are applicable with a) DC only b) AC only c) DC & AC

14 Answers   Bhel, Engineers India, Engineers India Limited,

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how can we connect a distance relay to CT core that is for backup protection or metering?

1 Answers  

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What is differential relay? How it operates?

1 Answers  

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power inverter we are using 2n3773 power transister in that places we can use any IGBT ?

1 Answers   Essar,

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Actually I have a doubt on neutral and earth.we use Ac power without taking neutral by connecting to earth,but at that time does it affects on efficiency of any electrical components or no? If yes how?

0 Answers  

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How we can calculate the Amps for the cable Ex:- For 1sqmm wire how many amps we can draw (calculation)

0 Answers   TATA,

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During Millivolt drop test current leads are applied in the extreme ends and voltage leads are given just before the current leads.. what will be the difference if voltage leads are given in the extreme ends? and why?

1 Answers  

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In 110V DC supply,if a closed circuit gets open, How can we identify the voltage which is measured after the resistor(4KOhm) which is open with negative.it shows 55V +ve when measured, also the actual positive source is 55V +ve .Because there is no voltage drop in open circuit. How can we identify whether this is the voltage which is series with the resistor or the DC source direct +ve.

1 Answers   GE,

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completed BE & done apprentice at tneb & having experience 6 years. want to get c license. will apprentiship & BE be helpful for getting c license. will i get any preference by showing this?

0 Answers  

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Why a transformer is rated in kVA and not in kW??

9 Answers  

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In CT, burden is 15 VA and protection 5P20,CT ratio is 100:1 then what would be the knee point voltage ?

2 Answers   ERL,

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Why is the neutral point of a star connected winding of a motor not grounded?

1 Answers  

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