USCO Power Switches

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DESIGN CHARACTERISTICS Contacts

Blade The blade is constructed of heat-treated aluminum tubing with heat-treated aluminum castings welded to hinge and jaw ends. Blade Mechanism The unique center break design of the ATR allows for better weight distribution of the blade assemblies without the need for ad- ditional phase spacing. The weight of the blades is distributed among the three insula- tors rather than all the weight balancing on the center insulator, as is the case with the double break switch. This increases rigidity of the blades while decreasing probability of contact misalignment, especially with higher rated switches.

The ATR is supplied with high-pressure silver-to-silver jaw contacts producing the highest conductivity initially and over time. The contact fingers, fabricated from hard drawn copper, are silver metallized and elec- tro-tin plated. The male contact, also of hard drawn copper, has a brazed silver overlay and is electro-tin plated. These methods and materials used in the application of the silver provide surfaces of differing hardness with anti-galling properties, resulting in minimal wear over years of operation. All contacts on the ATR are field replaceable. The ATR uses USCO’s time tested welded lamination hinge assembly producing a straight-line current path eliminating any current transfer at the hinge. This is accom- plished with a welded aluminum laminated conductor that is used to create a bypass at the hinge. This eliminates the need for bolted or sliding pressure connections, or high pressure contacts, and enables ease of operation. The welded connections create a single metallic path from the hinge termi- nal pads to the main contacts on the blades of the switch. The laminated conductor is constructed of commercially pure aluminum strip, which does not work harden during operation.

D O U B L E C E N T E R B R E A K

ACCESSORIES • Grounding switches: Through 100kA momentary • Auxiliary switches: 12 contact decks are standard • Standard arcing horns are installed on all group operated switches • Outriggers: Custom designed for your application • Connectors: Available on all switch types

HUBBELL / USCO  – LEEDS, ALABAMA USA

SEPTEMBER 2013