1)Why potential transformer primary site grounded?
2)can be loop between neutral & body for grounding?
3)What is the difference between ELCB &RCCB?
4)Why we use iron core in transformer insted of wooden core?
5)what is the principle of excitation?
6)Why we test the core balance test for transformer?
7)what is creepage?What is the creepage length for
insulators at different voltages?
8)How much type of relays used for differential protection
of generator,transformer & busbar protection?
Answers were Sorted based on User's Feedback
1. Here the HV or LV of THE TRANSFORMER is not concerned.
The star side of the transformer is grounded. i.e the
neutral of the star side is grounded for detecting the
earth fault current in case of earth fault in the protected
zone of the transformer.
2. No the body and the neutral should be grounded
separately . because huge fault current can flow in the
body and other auxilliary protection in case of a earth
fault.
8. Differential protection relays are used. eg ABB
SPAD346C1,c2,c3, Siemens 7ut612 etc .
Is This Answer Correct ? | 3 Yes | 2 No |
Answer / arb555
1) Usaully relays are connectd in 2ndary . SO to detect faults
2) no
3)ELCB detects phase to earth faults
RCCB - trips if net current is not zero
4) to incresae the permeability
if air used-air core
iron -iron core
no wood- its an insulator
5) Dc fiels required in generators for excitation.
7)I think its the distance b/w insulaotors.
8) Merz pRice circulating current basd relays are common
Better answers always let me know !
Is This Answer Correct ? | 2 Yes | 1 No |
Answer / manishkalia09
ans not know.
please give me anser of these questions.
Is This Answer Correct ? | 3 Yes | 3 No |
Answer / abcd
ELCB detects phase to earth faults.It can detect low impedence faults but on the contrary if there occurs a high impedence fault in the system then the fault current may be very small. Such faults are detected by RCCB.
Is This Answer Correct ? | 0 Yes | 0 No |
Answer / sparta
1. to measure the voltage of the phase we used to ground
the PT ,
2.no
3.
Is This Answer Correct ? | 0 Yes | 3 No |
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