Abstract: A medium voltage controller for electrical equipment, having cast fuse holders, a disconnect switch, a switch illuminator, low power current transformers, and an optical temperature measuring system. The fuse holder includes a cast housing with smooth rounded surfaces that reduce corona. The disconnect switch has cast components that provide terminal points, mounting surfaces, and contact surfaces. The switch illuminator provides illumination of the disconnect switch internals. The contactor assembly is mounted in a truck and moves on a rail system that includes a pull-down handle with rails. The truck rolls out of the cabinet on the extended rails for easy removal from the cabinet. The truck, and contactor assembly, is racked in by pushing the truck into the cabinet and then raising the handle, which forces the draw-out fingers to engage the contact stabs.

Abstract: A machine operator control station circuit which uses capacitive proximity switches to replicate the function of mechanical switches used in prior art control stations. A monitoring circuit for monitoring the "on" state of the capacitive proximity switches used in a two hand industrial machine control station is disclosed. The circuit also reduces the chance of unintended operation of the machine being controlled as a result of emitted or conducted radio frequency interference which might be detected by the capacitive proximity switches. An isolation transformer provides an isolated power supply for the monitoring circuit. The monitoring circuit includes a first capacitive proximity switch for detecting the presence of one of the machine operator's hands, and a second capacitive proximity switch for detecting the presence of the other of the machine operator's hands. Each proximity switch has a monitoring circuit for monitoring the length of time the proximity switch remains in the activated or "on" state.

Abstract: The improved plug-in base assembly of the present invention provides a means for complying with European Health and Safety requirements and particularly the requirement of IEC 439-1 paragraph 7.4.2.2. Subparagraph 7.4.2.2.3 generally requires that live parts be shielded such that they cannot be contacted when a door or cover normally protecting them is opened or removed. This requirement provides additional protection to the installer of a tap-off device against unintentional contact with the uninsulated edges of bus bars exposed through the plug-in openings. The additional protection is provided by a finger barrier which covers the normally exposed uninsulated edge of a bus bar. The finger barrier permits the electrical connectors of a tap-off unit to pass through the plug-in opening and make an electrical connection while preventing any unintentional contact of the installers fingers with the uninsulated edge of the bus bar.

Abstract: The rotational optical switch of the present invention includes a switch enclosure, a light conductor, an optical shutter, a torsion spring biasing the shutter towards a bistable state, and a shutter actuator. The switch enclosure generally encloses the remaining components. The light conductor is received in the switch enclosure and extends between the enclosure and a transceiver, which provides a signal reflective of the state of the optical shutter. The optical shutter is pivotally mounted within the switch enclosure and is bistable between a reflective state which reflects light into the light conductor, and a nonreflective state which does not reflect light into the light conductor. The shutter pivots on arms to either end of a support cylinder which have knife edges. The shutter actuator is pivotally connected to the optical shutter by the torsion spring to cause the optical shutter to snap between the bistable states. The optical shutter has two reflectors in opposite reflective states.

Abstract: A floor construction includes a metal floor decking having a plurality of parallel multi-cell cellular metal floor raceways each of which includes at least one cell for high voltage power wiring. This one cell has a first wiring opening defined in a top thereof. A limited access feeder raceway transversely spans and rests upon the cellular metal floor raceways. The feeder raceway includes an enclosed first wiring raceway separating bottomless second and third wiring raceways. The enclosed first wiring raceway has a plurality of spaced second wiring openings defined through a bottom thereof, one of said second wiring openings being located directly above and in registry with each of the first wiring openings. The feeder raceway includes a closed top having a plurality of spaced access openings defined therethrough, one of which access openings is located directly above each of the second wiring openings.

Abstract: An underfloor duct designed to be imbedded in a concrete floor is constructed from first and second duct partial sections which are held together by an interlocking structure integrally formed from the sheet metal of the duct partial sections. In a preferred form the duct partial sections are duct half sections substantially identically formed from sheet metal. In another preferred form, the duct partial sections define flanges extending outwardly at an intermediate level along the sides of a rectangular cross section duct, whereby the duct may be supported from the flanges. Also, multiple cell duct configurations are disclosed.