MGVCL Exam Paper (30-07-2021 Shift 2)
Consider the following statements associated with Buchholz's relays. Statement 1: Buchholz's relay is a current operated device. Statement 2 : Buchholz's relay is placed between the transformer tank and the conservator.
Buchholz relay is gas operated relay. It will operate when internal fault occurs in transformer. It is placed between tank to main conservator. It has two contacts trip and alarm. Use of Buchholz relay in distribution transformer is not economical.
Frequency response analysis is the technique whereby a sinusoidal test signal is used to measure points on the frequency response of a transfer function or impedance function. Sweep Frequency Response Analysis (SFRA) testing provides insight into the mechanical and electrical integrity of transformers.
Main Purpose of SFRA Test: Transformer Core displacement Winding displacement for both rotor and transformer Broken or loosen clamp connections Inter turn short circuit Internal short circuit Winding to Core Earth fault Winding Open circuit condition
In single phase energy meter, Current coil is made up from thick wire having few no. of turns. Pressure coil is made up from thin wire having more no. of turns.
EXAMIANS