摘要:
A lead weight or other mass is crimped to the contact button assembly of the arcing rod of a high-voltage alternating-current power fuse thereby increasing the mass of the arcing rod without increasing the diameter of the rod. The increased mass of the arcing rod decreases the velocity with which the arcing rod moves upon fusing of the fusible member thereby decreasing the rate of elongation of the arc drawn between the end of the arcing rod and the stationary ferrule at the other end of the fuse. Under high current conditions, the shorter arc length drawn in the fuse reduces the pressure of the arc-extinguishing gas generated by the arc, thereby reducing the risk that an economically constructed fuse will burst in those situations when the arc is not interrupted at the first current zero. This result is accomplished without adversely affecting operation of the fuse and interruption of the arc at low current levels.
摘要:
A low-exhaust composite drop-out assembly is provided that is utilizable in a standard cutout mounting in electrical power distribution systems. The composite drop-out assembly includes current-limiting and low-current clearing sections and is easily removable from mounting for servicing. The sections are efficiently arranged in a side by side configuration.. The low-current clearing section includes a fuse-robe assembly having a replaceable fuse cartridge. Accordingly, the low-current clearing section is simply and economically renewable for reuse whether or not the current-limiting section has operated. Further, the current-limiting section need not be replaced if only the low-current clearing section operated in response to overcurrent in a low range. Additionally, the sections are separable so that the low-current clearing section can be reused after simple refusing even when the current-limiting section has operated.
摘要:
A low-exhaust composite drop-out assembly is provided that is utilizable in a standard cutout mounting in electrical power distribution systems. The composite drop-out assembly includes current-limiting and low-current clearing sections and is easily removable from the mounting for servicing. The sections are efficiently arranged in a side by side configuration. The low-current clearing section includes a fuse-tube assembly having a replaceable fuse cartridge. Accordingly, the low-current clearing section is simply and economically renewable for reuse whether or not the current-limiting section has operated. Further, the current-limiting section need not be replaced if only the low-current clearing section operated in response to overcurrent in a low range. Additionally, the sections are separable so that the low-current clearing section can be reused after simple refusing even when the current-limiting section has operated.
摘要:
A valve arrangement for high voltage fuses permits the atmosphere to be vented into the interior of the fuse when the atmospheric pressure is greater than the interior pressure of the fuse, but restricts venting back out of the fuse when the interior pressure of the fuse is greater than atmospheric pressure thereby tending to maintain a greater than atmospheric pressure on the inside of the fuse to assist in preventing moisture from entering the fuse. The valve arrangement also enhances fuse operation. During the interruption of relatively low current, it functions as a check valve and tends to assist in increasing the internal pressure within the fuse thereby tending to accelerate contact separation. However, at higher current levels the valve arrangement ruptures, releasing the arc gases so that there is not an adverse effect on fuse operation.
摘要:
A pull-ring for an electrical device, such as a high-voltage fuse, which may be placed in a mounting. The pull-ring operates a latch, which is capable of holding the fuse closed in the mounting, only when it is reciprocated. The pull-ring is pivotable independently of its reciprocation without affecting the condition of the latch. Accordingly, when a trunnion on the device is in a hinge of the mounting and a pushing force is applied to the pull-ring with a tool to close the device, the natural decrease in the interior angle between the tool and the device can rotate the pull-ring without preventing the latch from holding the device closed. Further, whether the pushing force or a pulling (opening) force is applied to the pull-ring, the direction of application of the force may be adjusted or may naturally change before, during,or after such force application with affecting the ability of the latch to hold the device closed. The tool may, therefore, be either a non-grasping tool (a "hot stick") or one (a "shotgun stick") capable of grasping the pull-ring. In the latter event, when the tool grasps the pull-ring and the trunnion is out of the hinge, the pull-ring is biased to a pivotal orientation whereat the trunnion is presented for convenient insertion into the hinge upon manipulation of the tool.