| 摘要 |
<p>A single-phase ground enclosed load break switch (205) for distribution voltages has a hermetically sealed cylindrical metal housing (210) of from 2 to 6 inches diameter which contains an insulating gas under pressure. The switch has a movable contact assembly (219) to contact a pair of opposed stationary coaxial conductors (224, 226) within the housing. Movement of the contact assembly (219) along one conductor (224) breaks the connection with the other conductor (226) and simultaneously reduces the sliding contact force on the first conductor (224). The switch has conductive bands (350, 352) coaxially positioned near the housing (210) around the conductors for low voltage measurements monitoring conductor energization and contact position. A rocking bellows (266) at the fulcrum of a crank actuator (264) provides a compact hermetic seal for the actuator without excessive strain of the bellows. A safety interlock with a visual indicator (318) locks the contact assembly in case of a loss of pressure. Excessive pressure in the switch (205) causes the bellows (266) to be punctured with consequent locking of the contact assembly. The switch (205) is small enough to be mounted directly on a transformer or placed into a cable, without the need for a separate enclosure.</p> |
