HIGH VOLTAGE MOTOR STARTER ENCLOSURE

摘要

HIGH VOLTAGE MOTOR STARTER ENCLOSURE of the Invention A high voltage motor starter enclosure includes a floor mounted vertical section consisting of three starter cells, stacked one on top of the other, each cell being suitable to mount one full voltage, non-reversing, squirrel cage starter having a contactor of the air break type. Each starter cell consists of four distinct, isolated compartments: a line and vertical bus compartment containing space for incoming line cables and vertical bus; a load compartment containing space for starter current transformers and motor cables for individual starters; a low voltage control compartment having a drawout, swing-open compartment door (panel) to provide easy access to meters, relays, pilot devices and terminal blocks for inspection and maintenance thereof; and a high voltage contactor compartment containing mechanical and electrical interlocks to minimize electrical hazards, a hinged door to provide easy access to a contactor and related component parts, and to the line and vertical bus, and load compartments by removing barrier cover plates. Wheel assemblies are mounted on each contactor so that the contactor rolls into both fully engaged and disengaged positions upon a contactor rail assembly which is part of a removable tray positioned beneath the contactor to support the same. The removable tray further includes several mechanical interlocks, a shutter operator mechanism for operating a shutter plate assembly to isolate the line and load terminals from the contactor, a positive ground connection assembly so that the contactor is grounded in the engaged and disengaged positions, a contactor stop assembly, and a bottom barrier plate for isolating the high voltage contactor compartments of each cell from one another. A drawout handle moves the contactor carriage upon the rail assembly, draws out the contactor disconnecting both line and load connections, and disconnects the primary of the control transformer. A thumbscrew mounted on the drawout handle functions as a mechanical and electrical interlock. When the thumbscrew is loosened or disengaged from a mechanical interlock of the drawout handle, it disconnects the secondary of the control transformer in the low voltage circuit of the contactor and it permits the drawout handle to be pulled down to draw out the contactor to a test position. A choke in parallel with normally closed contacts is inserted in series with the contactor coil after the coil is energized and the contacts open to act as an economizing circuit. Control transformer fuses are mounted directly to the power fuse stop bracket to prevent any nonfused protected wire between the high voltage source and the control power transformer's high voltage primary.