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Controls for the reclosers range from the original electromechanical systems to digital electronics with metering and SCADA functions. The ratings of reclosers run from 2.4–38 kV for load currents from 10–1200 A and fault currents from 1–16 kA. [7] [8] On a 3-phase circuit, a recloser is more beneficial than three separate fuse cutouts.
While the recloser does in fact help to break up distribution circuits into smaller, more manageable pieces, many protection schemes involving circuit breakers in distribution substations also apply reclosing to some extent, thus not "blacking out" the circuit and requiring a crew go to the station and reset a lockout.
In 1956, Hugh C. Ross at Jennings Radio Manufacturing Corporation revolutionized the high-frequency-circuit vacuum switch and produced a vacuum switch with a rating of 15 kV at 200 A. Five years later, Thomas H. Lee at General Electric produced the first vacuum circuit breakers [2] [3] with a rated voltage of 15 kV at short-circuit breaking ...
Electromechanical protective relays operate by either magnetic attraction, or magnetic induction. [9]: 14 Unlike switching type electromechanical relays with fixed and usually ill-defined operating voltage thresholds and operating times, protective relays have well-established, selectable, and adjustable time and current (or other operating parameter) operating characteristics.
A residual-current device (RCD), residual-current circuit breaker (RCCB) or ground fault circuit interrupter (GFCI) [a] is an electrical safety device, more specifically a form of Earth-leakage circuit breaker, that interrupts an electrical circuit when the current passing through line and neutral conductors of a circuit is not equal (the term residual relating to the imbalance), therefore ...
Circuit breakers with higher ratings can have adjustable trip settings, allowing fewer standardized products to be used, adjusted to the applicable precise ratings when installed. For example, a circuit breaker with a 400 ampere frame size might have its over-current detection threshold set only 300 amperes where that rating is appropriate.
Silver whiskers growing out of surface-mount resistors Metal whiskering is a phenomenon that occurs in electrical devices when metals form long whisker-like projections over time. Tin whiskers were noticed and documented in the vacuum tube era of electronics early in the 20th century in equipment that used pure, or almost pure, tin solder in ...
Single-chip AM radio integrated circuit from 1972. LM317: Adjustable 1.5 A positive voltage regulator (1.25 V-37 V) [8] LM13700: Two current controlled operational transconductance amplifiers (OTA), each having differential inputs and a push-pull output. LM393 No Dual Differential Comparator [9] LM358: No Low power, wide supply range dual op ...