Abstract: A refrigerant compressor system suitable for transport refrigeration applications, including a refrigerant compressor, an electric motor and a hydraulic motor directly coupled together within a common housing. The electric motor includes a stator and a rotor, with the rotor having first and second axial ends. The refrigerant compressor is coupled to the first axial end of rotor, and the hydraulic motor is coupled to the second axial end. A single housing surrounds the electric motor, the refrigerant compressor, and the hydraulic motor. Hydraulic fluid for driving the hydraulic motor is selected to be compatible with the lubricating oil of the refrigerant compressor, such that leakage of hydraulic fluid into the housing will not adversely affect operation of the refrigerant compressor system. The housing is directly connected to a selected side of an associated refrigeration system, with the suction side being preferred, enabling the housing to also function as a refrigerant accumulator.

Abstract: A mechanical interlock device for preventing simultaneous operation of two 3-phase vacuum interrupter-type circuit breakers is provided. The device operates with the floor tripper and the Mechanism Operated Control ("MOC") driver of each vacuum circuit breaker. The device includes a retainer member mounted at the base of each circuit breaker. Each retainer member includes two levers. The first lever is a trip lever which engages the floor tripper of the associated circuit breaker. The second lever is driven by the MOC driver of the associated circuit breakers. The two levers are preferably mounted on a common pivot bar located at one end the retainer member. Cabling is provided between the trip lever on the first circuit breaker and the MOC driver lever on the second circuit breaker. Similarly, a cable is provided between the MOC driver lever of the first circuit breaker and the trip lever of the second circuit breaker.

Abstract: A generic tool is provided by storing into a PC computer data representing structurally a vertical section and objects to be placed inside the vertical section, and by manipulating virtually with the PC computer selected objects in relation to cases within the vertical section while testing the physical compatibility, so as to build a feasible product configuration to be visually shown by the PC computer as an aid in the actual installation manually of the product with actual such objects and vertical section, for instance to build up a panelboard.

Abstract: A circuit breaker having a contact movable between open and closed positions, includes a closing spring assembly having a closing spring and first and second brackets. The closing spring assembly is chargeable when in a reset position in which the first bracket is hooked by a first hook. The closing spring is charged, manually or electrically, with support of the second bracket being transferred to a second hook. The closing spring is discharged to close the circuit breaker, with the closing spring assembly moving from the reset position to a discharged position in the process. The closing spring assembly is then moved as an integral unit, back to the reset position, with the closing spring again being charged, enabling the circuit breaker to immediately reclose in the event of a trip due to a transient condition. An improved breaker operating mechanism and power operated charging mechanism, are also disclosed.

Abstract: A method of detecting conditions during the operation of a transport refrigeration unit (20) which may cause shutdown, and then modifying the operation of the unit in an attempt to find an operating condition that will keep the unit operating safely. The unit includes a compressor (26) driven by an engine (30) operable at low and high speeds. Upon detecting (264) an over-temperature condition of the engine a first modification (282) is initiated, including switching the engine to low speed. If the engine temperature does not drop to a safe value (288, 292), a second modification (296) is initiated. If the engine was in low speed (280) when the over-temperature condition was detected, the second modification is initiated immediately. Upon detecting (314) a low oil pressure condition, the engine is switched (316) to high speed. If the oil pressure rises to a safe level, engine operation is continued at high speed. Appropriate alarms (326) accompany the modified operating conditions.

Abstract: A circuit breaker bandwidth limits a sensed rate of change of current, di/dt, in the neutral conductor of a protected electrical system and fullwave rectifies the bandwidth limited di/dt signal for comparison with an instantaneous trip reference signal. The bandwidth is selected to provide a selected relative sensitivity of the instantaneous trip to sinusoidal currents associated with overcurrent faults and step currents associated with sputtering arc faults. The rectified bandwidth limited di/dt signal is also filtered and delayed for comparison with a delayed trip reference signal. The time constant for the filter is selected to provide a selected relative sensitivity of the delayed trip to overcurrent faults and sputtering arc faults. A low mu sensing coil used to generate the di/dt signal can also serve as the neutral current sensing coil of a dormant oscillator ground fault protection system.

Abstract: A transport refrigeration system having separate evaporator and condenser units, with the condenser unit being mountable in either a vertical or a horizontal orientation. The condenser unit includes a frame supporting a condenser coil, a compressor and a refrigerant receiver. The compressor is a dry sump compressor having a predetermined centerline, with the compressor being operable with said predetermined centerline in any orientation within 45.degree. of a vertical centerline through the compressor. The compressor is oriented on the frame such that when the frame is oriented for vertical mounting the predetermined centerline of the compressor defines a first angle of about 45.degree. with the vertical centerline, and when the frame is oriented for horizontal mounting the predetermined centerline of the compressor defines a second angle of about 45.degree. with the vertical centerline, with the first and second angles being on opposite sides of the vertical centerline.

Abstract: A rotary handle operator for a circuit breaker with a linearly movable handle has a housing which is mounted over the circuit breaker handle. A slide carrying a rack engages the circuit breaker handle and is slidable within a chamber in the housing. The rack engages a pinion gear sector mounted on a rotatable shaft which extends through a cover on the housing. A rotating handle mounted on the shaft is rotated to linearly operate the circuit breaker handle or is positioned thereby when the circuit breaker trips. The handle may be locked in the off position by inserting the shackle of a lock through an aperture in a lever arm on the rotating handle to urge a pin on a spring biased locking piece within the handle lever into an aperture in the housing cover, or the shackles of several locks may engage a slot in a shroud surrounding the rotating handle to interfere with rotation of the handle out of the off position.

Abstract: A method and apparatus for remotely displaying information about heat in a motor having an associated motor-starting contactor with an overload relay system is provided. The apparatus includes a suitably programmed microprocessor which obtains a signal representative of current in the motor, squares the current and multiplies by time. This actual I.sup.2 t value is then used to calculate a signal representative of a relationship between the actual I.sup.2 t value and a target value at which the contacts of the motor-starting contactor will open due to an overload current situation. This relationship is preferably a percentage which is then displayed on either an LED bar type display or a digital display. The display may also include a "trip" indicator and a "reset allowed" indicator.

Abstract: A pair of lock links straddling and pivoted on the same pin as the latchable cradle of a circuit breaker follow the toggle device of the breaker either by riding on the toggle knee pin or through a pin which bears against the edges of the toggle arms. The lock links have extensions which engage the handle yoke to prevent the handle from being moved to the off position when the circuit breaker contacts are welded closed causing the toggle device to remain erected.

Abstract: A UPS system which operates initially in a commutation mode allowing commutation of the static transfer switch provided on the primary supply lines, and wherein the standby source is kept energized so as to operate to commutate such transfer switch through the inverter just before initiating UPS mode of operation.

Abstract: A molded gasket for a line conductor in a circuit breaker acts as a gas seal to prevent ionizing gases resulting from a circuit interruption from flashing over and causing phase-to-phase and phase-to-ground faults. The molded gasket includes provisions for sealing the line conductor at the interfaces with the circuit breaker housing as well as providing a barrier for the movable contact arm assembly.

Abstract: An insulated neutral bus has a base, top and conductive bus therebetween. Ribs extend from the base and frictionally engage ribs extending from the top. A recess is preferably provided in the bus so that the bus may fit behind a removable panelboard interior.

Abstract: Apparatus for producing plastic parts with a resilient projection, such as connectors for corrugated tubing. The apparatus includes means for flowing plastic material on a core provided with a recess to mould the resilient projection, plural core cam surfaces to extract the resilient projection out of the recess, after the mass of plastic material is solidified and extract the solidified part from the core.

Abstract: A mechanism for bypass isolation switches of the type comprised of at least three circuit interruption devices each having a handle has at least three switch gears, one positioned over each circuit interruption device and having either a drive gear or a spacer gear therebetween. A cam having a mouth which engages the handle of the circuit interruption device is eccentrically mounted on each switch gear. A stop is provided on at least one gear to permit the gears to rotate only 180.degree.. Since the drive, spacer and switch gears are interconnected, the cams must move or not move simultaneously. As a result, the at least three circuit interruption devices are operated simultaneously.

Abstract: Apparatus is provided for an electrical circuit breaker for preventing the handle thereof from being moved to the OFF position when the electrical contacts of the circuit breaker are welded closed. This apparatus mechanically limits the travel of the operating handle so that it may not be moved to the OFF position when the electrical contacts are closed. This restrictor apparatus as it is called is mechanically connected to, but out of direct contact with the handle arm of the circuit breaker. The mechanical linkage between the operating handle and the contact arm of the circuit breaker includes a projection. During the foregoing condition, the projection will interact with a crossbar assembly for the contact arm of the circuit breaker.

Abstract: A circuit breaker, and method of constructing same, in which a levering-in mechanism may be added after the circuit breaker has been assembled. The circuit breaker includes a chassis having first and second side plates which define upwardly open slots, which enable the levering-in mechanism to be "dropped in" to the correct position of an assembled circuit breaker, with bottom portions of the slots functioning as half bearings. First and second retainer plates with downwardly open slots are respectively attached to the first and second side plates, to complete the half bearings and hold the levering-in assembly. The levering-in mechanism includes a threaded shaft having a traveling nut, with a bushing on the shaft being held radially, but not axially, by a bracket member, with the bushing also functioning as a non-stress stop for the traveling nut.

Abstract: A logic level interlock device for an electrical contactor having an armature carrying separable contacts is provided. The interlock includes a plunger which is movable with the armature as the armature moves between its open and closed positions. A logic level sensing means is provided adjacent the plunger. An activation means which is sensed by the logic level sensing means is carried by the plunger member. In one embodiment of the invention, the sensing means is a set of magnetic reed switches which are activated by a permanent magnet carried on the plunger. In another embodiment of the invention, the sensing means is an opto-coupler circuit. The activation means carried on the plunger is perferably an opening which allows the infrared radiation to pass through to the receiver portion of the opto-coupler. In accordance with yet a further embodiment of the invention, the sensing means are two inductive sensing elements which are activated by a permanent magnet or a ferrite bead.

Abstract: A circuit breaker having a housing, fixed and movable contacts respectively supported by a fixed contact support structure and a movable contact arm, a trip mechanism, and an operating mechanism which is releasably engageable with the trip mechanism. The operating mechanism includes a pivotable operating member and a tension spring. The fixed contact support structure includes a contact supporting leg portion. The movable contact arm has a contact supporting side, and an opposite spring supporting side. The tension spring links the pivotable operating member and the spring supporting side of the movable contact arm. The contact supporting leg portion of the fixed contact support structure and the movable contact arm are disposed in closely spaced relation when the fixed and movable contacts are in engagement, to provide a reverse current loop which magnetically assists in rapid contact separation.

Abstract: An electric operator having a reciprocally mounted actuator is adapted to be mechanically coupled to an operating handle from a molded case circuit breaker or a molded case switch for moving the operating handle between an open position or, alternatively, to a closed position. The electric operator includes an electric motor for driving the actuator and allowing the circuit breaker to be controlled from a remote location and a mechanical crank assembly which alternatively allows for manual operation of the actuator in the event of a loss of electric power to the electric motor.