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Unformatted text preview: ples of Power System this way, a fuse protects the machines and equipment from damage due to excessive currents. It is
worthwhile to note that a fuse performs both detection and interruption functions.
3. Circuit breakers. A circuit breaker is an equipment which can open or close a circuit under
all conditions v iz. no load, full load and fault conditions. It is so designed that it can be operated
manually (or by remote control) under normal conditions and automatically under fault conditions.
For the latter operation, a relay circuit is used with a circuit breaker. Fig. 16.1 (i) shows the parts of
a typical oil circuit breaker whereas Fig. 16.1 (ii) shows its control by a relay circuit. The circuit
breaker essentially consists of moving and fixed contacts enclosed in strong metal tank and immersed
in oil, known as transformer oil.
Under normal operating conditions, the contacts remain closed and the circuit breaker carries the
full-load current continuously. In this condition, the e.m.f. in the second...
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This note was uploaded on 11/12/2012 for the course MBA 101 taught by Professor Muhannad during the Spring '12 term at Bradford School of Business.
- Spring '12