Abstract: A fusible disconnect switch includes a switch housing, and a first fuse contact member and a second fuse contact member coupled to the switch housing, each of the first fuse contact member and the second fuse contact member configured to engage and complete an electrical connection through an overcurrent protection fuse. The fusible disconnect switch further includes a switch contact including a parallel contact configuration. An interlock is operatively coupled to the first fuse contact member and a switch that operates the switch contact, the interlock configured to inhibit movement of the switch from the OFF position to the ON position when the first fuse contact member is unsecured to the switch housing, and inhibit movement of the first fuse contact member relative to the switch housing when the switch is in the ON position.

Abstract: A fusible disconnect switch includes a switch housing, and a first fuse contact member and a second fuse contact member coupled to the switch housing, each of the first fuse contact member and the second fuse contact member configured to engage and complete an electrical connection through an overcurrent protection fuse. The fusible disconnect switch further includes a switch contact including a parallel contact configuration. An interlock is operatively coupled to the first fuse contact member and a switch that operates the switch contact, the interlock configured to inhibit movement of the switch from the OFF position to the ON position when the first fuse contact member is unsecured to the switch housing, and inhibit movement of the first fuse contact member relative to the switch housing when the switch is in the ON position.

Abstract: Methods and apparatus to control zone temperatures in a solar cell production system are disclosed. An example furnace to fire photovoltaic cells includes: a plurality of zones comprising firing elements configured to fire a metallization layer of photovoltaic cells by heating the photovoltaic cells in the zones; one or more belts configured to transport photovoltaic cells through a sequence of the plurality of zones; a user interface comprising one or more input devices; and control circuitry configured to: control the firing elements for the plurality of zones; and modify a configuration of two or more of the plurality of zones based on input received via the input device.

Abstract: A circuit arrangement for a surge protection device for protecting multiple DC or AC power lines. The circuit arrangement includes a plurality of DC or AC power line inputs, a negative potential or neutral input, a ground potential input, a surge protection component having one or more surge elements, a rectification circuit including a plurality of diodes, and an alarm circuit for receiving a status output from the surge protection component.

Abstract: A circuit arrangement for a surge protection device for protecting multiple DC or AC power lines. The circuit arrangement includes a plurality of DC or AC power line inputs, a negative potential or neutral input, a ground potential input, a surge protection component having one or more surge elements, a rectification circuit including a plurality of diodes, and an alarm circuit for receiving a status output from the surge protection component.

Abstract: A method for detecting an arc fault in AC circuits. The method includes monitoring disturbances in an AC voltage signal by analyzing multi-dimensional energy points. A voltage signal is captured and the zero-crossing, minimum peak, and maximum peak are identified. Arcing signatures between the maximum and minimum peaks of the captured AC voltage signal are analyzed to detect an arc fault.

Abstract: Methods and apparatus to control zone temperatures in a solar cell production system are disclosed. An example furnace to fire photovoltaic cells includes: a plurality of zones comprising firing elements configured to fire a metallization layer of photovoltaic cells by heating the photovoltaic cells in the zones; one or more belts configured to transport photovoltaic cells through a sequence of the plurality of zones; a user interface comprising one or more input devices; and control circuitry configured to: control the firing elements for the plurality of zones; and modify a configuration of two or more of the plurality of zones based on input received via the input device.

Abstract: A method for detecting an arc fault in AC circuits. The method includes monitoring disturbances in an AC voltage signal by analyzing multi-dimensional energy points. A voltage signal is captured and the zero-crossing, minimum peak, and maximum peak are identified. Arcing signatures between the maximum and minimum peaks of the captured AC voltage signal are analyzed to detect an arc fault.

Abstract: An electrical test switch has an integral energized circuit indicator. The energized circuit indicator is integrated into the front and/or rear covers of the test switch. The energized circuit indicator is passive and senses properties of the at least one conductor of the device being tested by being placed in proximity of the device. The voltage display provides personnel a visual indication of whether the electrical device being tested is energized without requiring a physical test or direct connection to the at least one conductor of the device being measured.

Abstract: A method for detecting an open current transformer in an electrical power system includes measuring for a voltage value on a secondary side of a current transformer. The method continues with observing the voltage value for a predetermined waveform and initiating corrective action in the electrical power system upon detection of the predetermined waveform.

Abstract: A protective switch assembly (100) includes switch position sensors (109) that sense switch blade (14) position and indicate whether one or more switches (104) are open. According to another aspect, the voltage and current of the switch circuits are monitored to determine switch position as well as overall circuit status.

Abstract: An electrical test switch has an integral energized circuit indicator. The energized circuit indicator is integrated into the front and/or rear covers of the test switch. The energized circuit indicator is passive and senses properties of the at least one conductor of the device being tested by being placed in proximity of the device. The voltage display provides personnel a visual indication of whether the electrical device being tested is energized without requiring a physical test or direct connection to the at least one conductor of the device being measured.

Abstract: A method for detecting an open current transformer in an electrical power system includes measuring for a voltage value on a secondary side of a current transformer. The method continues with observing the voltage value for a predetermined waveform and initiating corrective action in the electrical power system upon detection of the predetermined waveform.

Abstract: A modular test switch assembly includes a plurality of stackable features that may be arranged in a variety of configurations. Each module includes a test switch and includes features to engage adjoining modules in the assembly. The entire test switch assembly is secured together using a retaining rod that is inserted through aligned thru-holes in the assembly.

Abstract: A protective switch assembly (100) includes switch position sensors (109) that sense switch blade (14) position and indicate whether one or more switches (104) are open. According to another aspect, the voltage and current of the switch circuits are monitored to determine switch position as well as overall circuit status.

Abstract: A modular test plug assembly is disclosed having a design which may be arranged in a plurality of different configurations. The test plug assembly includes a plurality of modules, having blades for insertion into a test switch assembly. The modules are positioned in a stacked arrangement and are secured together by end plates and a rod extending therebetween.

Abstract: A modular test switch assembly includes a plurality of stackable features that may be arranged in a variety of configurations. Each module includes a test switch and includes features to engage adjoining modules in the assembly. The entire test switch assembly is secured together using a retaining rod that is inserted through aligned thru-holes in the assembly.

Abstract: A modular test plug assembly is disclosed having a design which may be arranged in a plurality of different configurations. The test plug assembly includes a plurality of modules, having blades for insertion into a test switch assembly. The modules are positioned in a stacked arrangement and are secured together by end plates and a rod extending therebetween.