VERTICAL BREAK SLANT (VBS)
Type VBSA (Aluminum) / Type VBSC (Copper)
Basic Ratings and Switch Types
The VBS switch ratings are as listed in Table 1, ANSI C 37.32 in ratings of 69kV through 230kV, 1200 Amp to 2000 Amp.
The rated withstand and radio influence voltages shall be as shown in Table A for installations below 3300 ft. altitude. Altitude correction factors per ANSI C37.30.2971, Table 1 will apply for higher altitudes. The momentary current withstand shall be as shown in Table B.
Live Parts and Application
Manufactured in either aluminum VBSA) or copper (VBSC), the VBS offers minimum phase spacing and is the most versatile for interrupter accessories. The intrinsic design offers stability under heavy terminal pad loading. TheVBS is ideal for substation and transmission applications, and mounting options include horizontal upright mounting, vertical mounting (up to 230kV) and underhung mounting (up to 230kV).
All hardware in the live parts is 300 series stainless steel and shall be no less than ½” diameter. The VBS arcing horns are ½” stainless steel.
Contacts
The exposed contacts shall be self-wiping, silver-to-silver and are of the reverse loop shoe type to increase contact pressure under fault conditions. All other current carrying contacts, including hinged end contacts, shall be silver - to - silver, unless sealed and insulated from contamination and corrosion. Internal sealed contacts may be either silver-to-silver or silver- to-copper. All exposed contacts, both fixed and movable, shall be replaceable in the field.
External silver-to-silver contact surfaces that are applied to copper are brazed silver alloy inlay to brazed silver alloy inlay. Minimum silver thickness shall be .010 inches. Contact springs are stainless steel.
Bearings
The rotating insulators on switches rated 115kV and above have stainless steel ball bearings in stainless steel races. Bearings are lubricated and sealed from contaminants with a breathable, dust proof seal. The rotating insulators on switches rated 69kV and below have either stainless steel bearings shafts in bronze bushing or stainless steel ball bearings as previously described.
