Abstract: A one way flow and return system for vapor cooled transformer heat exchangers employs an inlet coupled with an entrance manifold and an outlet coupled with a return manifold. The incoming vaporized coolant enters the entrance manifold in a first direction of flow and the condensed vapor droplets leave the exit manifold in an opposite flow direction. The arrangement of separate entrance and exit manifolds prevents interference between the incoming vaporized coolant and the returning condensed coolant.

Abstract: Voltage surge arrester devices having predetermined shunt gap sparkover voltages are provided by the series combination of high- and low-exponent varistors. In one embodiment the high-exponent varistor comprises zinc oxide and the low-exponent varistor comprises silicon carbide.

Abstract: A high current furnace transformer is provided having the low-voltage windings arranged in a closed delta configuration within the transformer enclosure. Bus bar terminals are mounted exterior to the enclosure for providing electrical connection with the low-voltage windings.

Abstract: An electrical feed through bushing for transformers multifunctionally uses the transformer coolant to cool the bushing conductor. The bushing is piped into the transformer oil heat exchanger.

Abstract: A voltage regulator to provide a wide range of regulation, especially useful with process control. The regulator is provided with an extra bushing connected to the exciting winding of the regulator. By this means two or more regulators may be connected with their exciting windings in parallel and their series windings in series to provide a desired wide range of regulation. The invention also encompasses a selector switch so that the regulator operating at the top of the regulating range may be interchanged with one or more other regulators to alternate the tap-changing duty among the various regulators. Automatic operation of the regulators is disclosed.

Abstract: An electronic time-of-day metering system is disclosed for measuring electrical power by at least two different mechanical recording devices depending on the time-of-day and time of week in which the electrical power is being consumed. A conventional kilowatt hour meter includes a set of decade gear driven dials which register the kilowatt hours consumed on a continuous basis. At least one other set of decade gear driven dials is provided for registering the consumption of kilowatt hours during preselected peak power usage intervals. A single MOS integrated circuit controls the operation of the alternate set of decade gear driven dials. This circuit utilizes as its time base the 60 Hz line voltage derived from the energy distribution system being metered. A clock circuit generates timing signals for a clock control circuit which includes a circulatory memory which is preprogrammed to contain the times at which one or more alternate sets of dials are to be actuated.

Abstract: A unidirectional drive assembly for a mechanically driven meter register includes a gear shift operated gear ratio mechanism which allows a dial on the meter register to be driven up-scale at a normal rate with the forward direction of rotation of the meter input drive and driven up-scale at a compensated or faster rate with the reverse direction of rotation of the meter input drive. The ratio of the gears of the gear ratio mechanism can easily be changed to provide ratios which compensate for meter drag when the meter is run in the inverted position so that the meter registers correctly when operated in either the upright or inverted position, or to provide ratios which make the meter dial run up-scale at a faster than normal rate when the meter is tampered with to make its input drive operate in the reverse direction of rotation.

Abstract: A compact voltage surge arrester employs a miniature series gap electrode arrangement in series with a plurality of zinc oxide varistors. The series gap arrangement provides the use of zinc oxide varistors without auxiliary heat sinks.

Abstract: A meter terminal unit for use in automatic meter reading systems of the type including a control center for transmitting commands to and receiving measurement data from the terminal unit via a distribution unit serving several terminal units. The terminal unit is selectively responsive to commands generated by the control center to carry out load control operations, encoder meter reading and store operations, or transfer previously stored meter data from the terminal unit to the control center in accordance with functions specified by the various commands.

Abstract: A vacuum interrupter latch release mechanism employs a pivotably mounted trigger action arm in cooperation with a support arm assembly to resist the force of a main spring until the normally closed interrupter must be opened. Rotating the trigger action arm causes a catch on the trigger arm to become disengaged from an associated stop provided on the support arm assembly and allows the support arm assembly to pivot under the force of the main spring while being resisted by its weaker support spring. The rotation of the support arm is accelerated by the main spring. After a short stroke, an associated linkage impacts a stop on the vacuum interrupter which then becomes opened. The large force of the main spring causes virtually no wearing effect on the catch and stop faces over long periods of continuous operation.

Abstract: Zinc oxide varistor protective devices for vapor cooled transformers are integrally located in contact with the transformer coolant liquid to provide cooling capacity to the zinc oxide materials. The zinc oxide varistors are prevented from becoming electrically unstable by keeping the varistor operating temperature at or below the boiling point of the coolant.

Abstract: An improved electrostatic shield assembly for power transformer windings provides a decreased shield to winding insulation spacing. The decreased spacing substantially improves the capacitive coupling between the windings and shield, reducing transient voltage oscillations within the windings caused by external lighting surges.

Abstract: Metal oxide varistors having a uniform wattage gradient across the varistor surfaces are provided by removing a thin layer of metal oxide surface material from the periphery of the varistors prior to applying an insulating collar and a silicone rubber encapsulation for the purpose of heat dissipation.

Abstract: A sound reducing baffle for air cooled electrical apparatus with a ventilated enclosure comprised of a box-like closure member positioned in front of the ventilating openings and open at the back and top thereof to permit the transfer of air.The sound is attenuated by reflections and absorption within the baffle with little or no interference with the transfer of cooling air to and from the enclosure.

Abstract: A gear and boss protector for the spring driving mechanism of a tap selector such as a voltage regulator. A pair of hook cams form the protective means and they are mounted rotatably on the crank driven by the spring driving gear. One of the hook cams engages the driving boss on the driving gear should the gear reverse rotation in one direction, while the other hook cam engages the driving boss on the driving gear should the gear reverse rotation in the opposite direction. The engagement of the driving boss by the hook cam prevents the crank from being suddenly released causing damage to the gear or boss.

Abstract: A data recording system includes a master tape recorder interconnected to a plurality of slave recorders. Each recorder is adapted to record meter data provided thereto from a meter associated with each recorder. The master recorder includes a timing circuit for effecting the recording of interval marks at periodic intervals on tape of all of the recorders as a time reference for the meter data of each recorder. The timing circuit also includes means for detecting a power outage to the recorders to generate a power outage pulse which effects the writing of a power outage indication by all of the recorders.

Abstract: An automatic meter reading and control system for communicating with remote terminal points includes a central station which selectively communicates with a transponder controller unit at each terminal point via a plurality of distribution units, each serving several transponder controller units. The distribution controller units are responsive to various commands issued by the central station to selectively route the commands to specified transponder controller units to direct the transponder controller units to selectively carry out a load control operation, a meter reading operation or transfer of previously stored meter data from the transponder units to the central station in accordance with functions specified by the various commands.

Abstract: Surge arrester spark gap assemblies for use within surge voltage arrester devices employ the gap electrode structure to direct the arc current flow.

Abstract: A method of welding aluminum to aluminum by thermal resistance welding, providing good electrical and mechanical characteristics. The method uses special electrodes for thermal heat that are hard and have a high electrical resistance, such as molybdenum or tungsten alloy and also relies on the aluminum oxide coating on the aluminum to provide the desired resistance heating of the aluminum to cause welding of the aluminum material. The machine disclosed provides a means for securing aluminum leads to the start and finish end of an aluminum winding automatically and simultaneously.

Abstract: A solid state, reverse power flow detector and control circuit which samples the line voltage and current, once each cycle. The voltage sampling circuit includes a pulse generator providing a voltage pulse of short duration at a given time or phase angle in each cycle. The voltage signals are applied to an SCR through a gate operated by the current signals. With forward or no current the voltage signals do not reach the SCR. When current reverses the voltage signals are allowed to trigger the SCR. The SCR turns on a transistor energizing a relay, after a brief delay. The relay acts to set the regulator or other device in power reverse condition. When current again is forward the relay is deenergized and the device returned to the power forward condition.