Answer / k.prakashchandra

For safety against probable high voltage of primary
appearing in the secondary ,due to either insulation failure
or capacitive coupling between primary and secondary ,as
earthing has reference to the primary voltage.

Answer / tamilarasu

Incase sometimes we want to change the ammeter or any c.t
using relay that time we shorted the s1,s2 tappings. incase
we forget the short of s1,s2.same time c.t burned& it
produce some dangers .so we reduse the danger from c.t
regarding the earthing

Answer / henry vakharia

Current transformers are classified in two categories viz.
protection and measuring classes.
In protection relay, the earth fault is detected from the
earthed terminal or say the common terminal shorted
together and then grounded, which makes the relay detect
the earthfault other than its core function of protecting
equipments from high voltage surges.
In measuring relay, the C.T. is grounded to give protection
from the primary high voltages surges.

Answer / d.lakshmi narayana

IN HT IN CT SECONDARY SOME VOLTAGE GENERATED.THIS IS ACTUAL
CONDITION. IN FAULT CONDITION IT IS INCREASED. ON THT TIME
CURRENT OPERATED COIL IS SOME TIMES IT WAS DAMAGED OR
SUPPOSE U R USING INTEGRATED RELAY SOME TIMES IT WAS DAMASED
THAT'S WHY THE CT SECONDARY IS EARTHED OTHERVICE MORE
VOLTAGE IS COMIG SOME TIMES THE CT OPERATED RELAY WAS
MALFUNCTIONING.
SO CT SECONDARY IS EARTHED

Sir i completed diploma in electrical from govt. Polytechnic dhanbad (jharkhand) . In 2012 . Now i am working in sail iisco plant . Sir i want to get electrical supervisory certificate for applying in ongc . From where i get this certificate please guide me procedure step by step

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Is motor current is dependent on load.

2 Answers  

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basic of electrical information where i can get? plz send the website which you know?

1 Answers  

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Why corona takes place?

4 Answers   L&T,

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Why breakers not synchronized when the synchroscope is going in the anticlockwise direction?

2 Answers  

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What information we need to prepare relay coordination chart

0 Answers  

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why two fuses are used in battery charging room?one in positive line and the other in negative line?do any DC system require two fuses?

1 Answers   HPCL,

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Just a silly question but just to make my curious mind bac to normal - Why was not 67 and 67N relays built into a single relay as i have noticed that the R,Y,B CT wiring end up into the 67 relay while the common of the R,Y,B CT wiring end up into the 67N relay. Then it was better if a single relay was manufactured just like the distance relay (21). Another question i would like to ask is - how do we know where the 67 and 67 N relay has to be placed.why is it not placed at the transformer bay? In the substaion that i am working -i have noticed that it is placed between a breaker and a common double bus bar and this line bay is connected to another substation at a remote place which is furthur connected to a load. B U S______CT for 67 & 67N ______Breaker _____ remot s/s. B A R

1 Answers  

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1.how to calculate energy units in our home at singe phase, 2.415V,63A wiring what will use thickness of wire

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What is the Powar consumption of fan low speed to full speed? is it same ?

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What is the importance of RESONANCE

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WHY RATING OF VCB NOT LESS THAN 630A

0 Answers  

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