Answer / balasubramanian

CT PT ratings are decided on
1. Class : Protection, metering (for CT)
2. Burden: The load of relays, cabling, etc.
3. Fault level: The thermal capacity of CT for bearing the
fault current for required time 1 sec, 3 sec etc.
4. The voltage level of the system

Answer / pradeep kumar

ct decied as per metering OR protection ct Use ct as per
metering that we can use the metering instrument of panel
OR control room 1A OR 5A

Answer / d.durga prasad

In CT

CT primary rating will be decided by its load current &
secondary will depend up on purpose of of selection (either
metering or protection )

In PT

It will always depend upon its system rating & in secondary
the class will be depend upon its purpose of its
utilization as same as in the CT secodary. but the voltage
level is always 110V in secondary of transformer.

what is different between DIGITAL and ANALOG?

2 Answers  

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my question is Megger of cable insulation or swgr board meggerring some values in one day 50mohms,some other day checking different values(20Mohms). this tell that some person tell that that values ok. how to identify the megger value is correct. pls tell me the answer.

2 Answers  

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We have a 12MW power plant & we inject 5-6MW power to Orissa GRID. For this we have a 33KV/11KV switch yard having 12.5MVA power transformer. Some times we draw power during emergency. It is observed that during Export or Import for load less than 500Kw the power factor is decreasing to 0.3 . This is happening only during export or import. During island condition TG power factor OK.Our capacitor bank is provided with our Power plant auxilliary load. Please suggest how I can we improve our power factor during low load (GRID).

3 Answers  

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explain the meaning of harmonic resonance

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Should transformer earthing pit, to be connect to earthing mat in Substation

4 Answers  

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What is the principle of residual protection?

0 Answers  

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What would cause a 240v choke that should give 110v out on a 16w lamp to gradually increase to 160v?

0 Answers  

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CALCULATE THE TOTAL VOLTAGE DROP AND SELECT THE CABLE SIZE IN MM-SQARE FOR A PANEL-262KW AT 110 METER FROM THE SOURCE SUPPLY , SUPPLY VOLTAGE 240/415

0 Answers   DEWA, Growth,

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How will A Medium voltage circuit breaker(11 kV voltage level) operate under short circuit fault condition whether It is having short circuit release like Low voltage circuit breaker or relay should be given?

0 Answers  

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what do you mean by earth fault in transformer?

2 Answers   L&T, UPL,

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Dear sir, I am working in wind mill division , pls explain Pls explain in details with formula My question is Wind speed 3.5 M/s Gen RPM is 1500 ( 25 K/w Production ) Wind speed 12 M/s Gen RPM is 1500 ( 220 K/w Production ) Why in 3.5 m/s generation was low , why in 12 m/s generation was high , Pls dont explain wind force or wind density , that one already i know For the above question RPM was same why the KW was different Answer : 1. Its depends on the density ( Force ) of the air Sir , Pls explain wit Formula sir

1 Answers   Vestas,

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