Answer / loganath

Motor protection relays are available in the market such as
Areva make MOTPRO, MiCOM P22X, but these relays are costly,
not used for small motors unless application warrants the
same, CT is required to connect with these relays unlike
direct connection for OLR

What are the types of Transformer? Name them.

9 Answers   Bhel, HSL, NTPC,

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Why we transmit the power at the voltage in the multiple of 11 or 1.1 like 11kv, 22kv, 66kv, 132kv...... some one told me that it is due to fomr factor 1.1 of sine wave. its fine but while transforming we can choose any voltage, so why only multiple of 1.1 there also.......? plz tell me.

7 Answers  

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why 30kva ups buzzing(hamming) sound?

2 Answers   Madhya Pradesh Electricity Board MPEB,

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Explain about 3 phase motor fault current calculation with examples?

0 Answers   QTC,

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What is LT? And specify the range of voltage?

10 Answers   HSL,

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My question is whether bellow formula is correct to find bus size for 46kA for 0.5 second & what is RT in bellow formula. formula to calculate the size of busbar to withstand the thermal stresses due to currents with duration of 0.2 sec to 5 sec. Sp = RT( I x I x t) / K Where Sp – is the cross sectional area of bus bar in millimeters. I -    is the value of AC fault current. t -    is the operating time of disconnecting device in seconds. K –  is the factor depending on the material of the conductor, insulation and initial and final temperature. Value of ‘k’ for copper is 143.

0 Answers   Premier,

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For small size, high frequency coils, the most common core material is- a. )Air b. )Ferrite c.) Powdered ion d.) Steel

0 Answers   Ecil,

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where we use zero sequence current transformer or core balancing ct.

2 Answers  

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How can we calculate earth mat conductor size ..? & give the formula to determine earth conductor size?

3 Answers  

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what happen if we give 220 volts dc supply to d bulb r tube light?

9 Answers   NHPC,

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Why tripping not occur when the transmission lines (11KV & above) breaks? Doesn't we provide earthfault protection for it?

1 Answers  

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Can we use Ccapacitive voltage transformer directly for metering purpose?

0 Answers  

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