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
Die-electric test on Circuit breaker: These tests are performed to check power frequency and impulse voltage withstand capacity. Power frequency tests are kept on a new circuit breaker, the test voltage changes with a circuit breaker rated voltage. In impulse tests, impulse voltage of particular value is employed to the breaker.
Type B MCB: Type B devices are generally suitable for domestic applications. They are designed to trip at fault currents of 3 - 5 times rated current.
Type C MCB: Type C devices are the normal choice for commercial and industrial applications These devices are designed to trip at 5 - 10 times rated current
Type D MCB: The Type D devices have more limited applications, normally in industrial use where high inrush currents may be expected. Type D devices are designed to trip at 10 - 20 times.
1.6 inches = 1.6 inches x 1,000 mils per inch = 1,600 mils 0.25 inch = 0.25 inch x 1,000 mils per inch = 250 mils Area = 1,600 x 250 = 400,000 square mils
EXAMIANS