Abstract: Model insulation structure representative of the most critical insulation in a stationary induction apparatus is placed in the bottom of the oil tank and is provided with spaced conductive electrodes forming a capacitor having sufficient capacitance for measuring the dissipation or power factor of the insulation.

Abstract: A signal voltage level sensing circuit particularly well adapted for use in a static overcurrent trip device. An operational amplifier is utilized to sense the difference between a signal voltage and a predetermined reference voltage while another operational amplifier is the memory element. Minimum duration of input signal to which the memory element responds is established by a resistor and a capacitor in conjunction with the threshhold of the memory element.

Abstract: A drawout switchgear having an in-line vacuum circuit breaker carried on a truck which is insertable into a compartment of the switchgear; the truck carrying the breaker is inserted into the compartment and the truck and breaker as a unit is elevated into the connected position; in connected position each vacuum interrupter is enclosed in its own stationary porcelain housing which also contains the primary disconnects that feed vertically directly to the main horizontal bus and up through long porcelain insulators to outgoing compartments at the rear of circuit breaker compartment.

Abstract: A vacuum switch with integrated capacitor shield comprising an evacuated insulating envelope provided with metallic end cap closures through which relative movable contact rods extend; the evacuated envelope encloses a plurality of shields which also serve as capacitor vanes permanently fixed to another shield and the stationary contact.

Abstract: A portable unit to maintain the dielectric integrity of the sulfur hexafluoride gas of a gas insulated metal-clad substation system without taking the substation out of service. The gas conditioner and analyzer provides the means for achieving the required control of the insulating gas by providing means for measuring the gas temperature, moisture and pressure, removal of moisture and products of decomposition from the gas, and, if necessary, replenishment of the gas.

Abstract: A detachable mounting and support arrangement for the stationary spray tube which extends through a rotary drum. A tension cable extends through the spray tube and is anchored exteriorly of the drum and spray tube at each end of the drum.

Abstract: A single pull-rod mechanism operatively arranged externally of gas insulated sealed enclosures for actuating the several contacts and associated blast valves of one or more circuit breakers. The mechanism is external of the enclosure to facilitate adjustment and servicing without the necessity of breaching the integrity of the gas sealed enclosures. Also provided is a selective mechanism for insuring that the blast valves are in closed positions and recoupled to the actuating mechanisms prior to the opening movement of the contacts.