Abstract: Improved shock and electrical-fire protection circuits provide line-to-ground plus "line-to-line" fault protection in a power system, and monitor conditions after protective interruption to safely provide automatic restoration of current when the fault is cleared. Both full-wave and half-wave circuits employ less expensive component combinations, including rectifiers and electromagnetic relays, to carry and switch load current. Protection is provided against the possibility of semi-conductor failure and the hazards associated with severed power conductors. A specialized resistance network fault detector for sensitizing enclosures, a hybrid zero sequence current transformer system and polyphase supply provide additional features.

Abstract: An electrical circuit, controlled by an electromagnetic relay, comprising an electromagnetic relay having relay contacts for controlling current flow to a load in use, and a relay winding which, when energized, causes closure of said relay contacts. First manually operable switch means is provided for energizing said relay winding, and a feed connection is provided from said relay contacts to said relay winding whereby said winding is energized while said contacts are closed. A second manually operable switch means for short circuiting said relay winding is provided to permit said relay contacts to open. An overload protection winding is physically associated with the relay winding and connected in series with the contacts, said overload protection winding being such that when the current flowing therethrough exceeds a predetermined value the electromagnetic effect generated opposes the electromagnetic effect of the relay winding to a sufficient extent to permit said relay contacts to open.

Abstract: A circuit breaker comprising two or more sections connected in parallel with each other. Each section of the circuit breaker comprises an electromagnetic sensing device and a pair of relatively movable contacts. The electromagnetic sensing devices are electrically connected at one of their ends to the load terminals. The load terminals are electrically connected in parallel with each other. The electromagnetic sensing devices are electrically connected at their other ends to each other and are electrically connected to all of the movable contacts which are themselves all electrically connected together. The stationary contacts are connected to line terminals which are also electrically connected in parallel with each other.

Abstract: A reset lockout addition to an A.C. overload current sensing, remote power controller of minimum size and weight and integral construction. Current rate sensing wound toroids are used that are small enough to fit around the line terminal studs without having to enlarge prior insulator space available therein. The electronic overload current detecting and tripping control circuit, is replaced by a pair of modules, detector and control modules, having improved performance and a shape and size such that they fit within the relay housing alongside its operating magnet. The detector module has integrator means for converting current rate of change signals into magnitude indicative signals thereby enabling use therewith of rate sensing wound toroids of about one-tenth the size of equivalent current transformer wound toroids.

Abstract: In a device for dispersing gas, e.g., air into a liquid or slurry in motion, wherein the surface at which dispersing takes place has a vertical extension and thus is subjected to varying hydrostatic pressure effected by the liquid or slurry, dispersing is optimized and the performance essentially improved by compensating the varying hydrostatic pressure with a dynamic pressure caused by the liquid in motion and varying in a desired manner so that the total pressure at least at most of the dispersing surface is substantially equalized. Said compensating is effected by providing for the correct flow rate and corresponding shape of the dispersing surfaces and other possible members influencing the liquid flow. In one embodiment the dispersing surface is represented by the envelope surface of a rotor rotating about a vertical axis.

Abstract: The sensing and trip circuit electronics of a ground fault interrupter of the differential current transformer type is, in a two pole system, supplied with power from each of the line conductors through separate solenoid trip coils and zener diodes that together provide good transient suppression while the zener diodes together provide full wave rectification for the voltage supplied to the electronics.