Goab overview for pdf - SEECO Southern Electrical ...

1 Southern Electrical equipment Company, Inc. Box 668547 Charlotte, 28266 Phone (704) 392-1396 Fax (704) 392-7033 E-Mail the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityIndustry Since 1920 Industry Since 1920 Industry Since 1920 Industry Since 1920 Industry Since 1920 Document PC-002-OverviewApril 15, 20021 GOABS(R) OverviewGOABS(R) OverviewGOABS(R) OverviewGOABS(R) OverviewGOABS(R) OverviewSEECO phase-over-phase GOABS switches are designed specifically for switch-ing applications in transmission environments. They provide economicalsectionalizing, and tap and tie switching points for circuit control. Mounted on asingle pole structure in the line, their use can minimize line right-of-way require-ments and significantly reduce the costs of land and equipment associated withconventional substation GOABS utilize side-break style switches, mounted horizontalupright on aluminum support structures.

2 The switch is designed for maintenance-free operation in severe environmental and operating conditions. The operating ef-fort to open and close the switch is minimal, even at higher voltages; no slamming isever required. The switch is positively toggled when in the fully closed position, sothe switch stays closed under adverse conditions, such as excessive pole deflec-tion, vibration, and galloping conductors, without the use of blade locks or otherlatching current-carrying path is all copper with silver contact buttons, which provide asilver to copper current transfer; no aluminum is ever used in the current path. Thecurrent ratings are based on a 30 degree temperature rise. Hinge and jaw assem-blies are high pressure devices and are permanently sealed, requiring no mainte-nance over the life of the switch. The design of the jaw (female) contacts is veryforgiving, allowing a substantial amount of pole/frame structure movement and de-flection without diminishing contact pressure or effectiveness of current provision of support frames eliminates the need for pole cross arms or braces,and the use of aluminum provides a beneficial combination of light weight and highstrength, which reduces pole structure design requirements and cost.

3 Frames havewelded construction which provides a rigid, stable platform to assure proper switchoperating rated 69 kV and below will mount on any suitable structure; switches rated115 kV and above will mount on steel, concrete, or laminated wood and Tie and Tie and Tie and Tie and Tap Switchingap Switchingap Switchingap Switchingap SwitchingTwo-way and three-way phase-over-phase switches employ a multiple-switch con-cept where individual switch pole units are arranged in an integral design, sharinginsulators, interrupters, and other switch components. Because components areshared, the cost of switching becomes proportionally less expensive when com-pared to other conventional switch configurations. In addition, the combining of twoor three switches into one bundle provides a single location for tap or tie circuitcontrol, whether local, remote, or automatic.

4 This facilitates the addition and use ofautomation equipment , such as motor operators, rtu s, and line sensors, which sup-port switch operation through supervisory control or auto-sectionalizing. Like thesharing of switch components, the sharing of automation equipment makes the costof control proportionally less Electrical equipment Company, Inc. Box 668547 Charlotte, 28266 Phone (704) 392-1396 Fax (704) 392-7033 E-Mail the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityIndustry Since 1920 Industry Since 1920 Industry Since 1920 Industry Since 1920 Industry Since 1920 Document PC-002-OverviewApril 15, 20022 Interruption DevicesInterruption DevicesInterruption DevicesInterruption DevicesInterruption DevicesHigh-speed, snap-out arcing horns are standard equipment on all type G GOABS.

5 They are suitable for interruption of limited amounts of line charging and transformermagnetizing addition of SEECO MONORUPTR vacuum interrupters to phase-over-phaseswitches provides full load-break capabilities, allowing the switch to be operatedunder conditions that exceed the capabilities of conventional arcing horn interrupter unit (column) is used per phase and is mounted on the stationary,non-rotating insulator; the interrupter unit is then shared by each way of the switches allow breakers to be reserved for their intended duty of faultinterruptions, reducing breaker wear, and reducing or eliminating service interrup-tions for switching DetailsConstruction DetailsConstruction DetailsConstruction DetailsConstruction DetailsSEECO phase-over-phase GOABS switches are designed for maintenance-freeoperation in severe environmental and operating conditions.

6 The switch compo-nents are heavy-duty and rugged in their design, yet the operating effort to open andclose the switch is minimal, even at higher voltages; no slamming is ever ultimate reliability, SEECO phase-over-phase switches utilize a unique con-struction of the current carrying components and an over-toggle adjustment (figure1) in the control mechanism. This combination of design features and adjustmentprocedure insures that the switch stays closed under adverse conditions, such asexcessive pole deflection, vibration, and galloping conductors, without the use ofblade locks or other latching devices. For the harsh, unforgiving conditions in trans-mission operating environments, it is the most reliable switch available. It is a provendesign validated by over 40 years of successful switch is directly connected to the operating mechanism through the rotatinginsulators, inter-phase pipe, lever arms, and crank arms (figure 2), and is in positivecontrol throughout the entire opening and closing operation.

7 The control mecha-nism is designed for efficient transmission of the operating force to the rotating insu-lator so that opening and closing of the switch can be effected in a smooth, continu-ous motion with minimal operating Blade-Clip Blade-Clip Blade-Clip Blade-Clip Assembly (Jaw) EngagementAssembly (Jaw) EngagementAssembly (Jaw) EngagementAssembly (Jaw) EngagementAssembly (Jaw) EngagementThe clip assemblies are held open (figure 3) at approximately 40 degrees by aclutch and double spring arrangement housed inside the base of the clip the blades swing closed, they engage the contact fingers, pulling the clipassemblies into the final, closed position. This simultaneous blade-clip assemblymotion enables the high-pressure, large contact deflection to be achieved with mini-mum operating effort and provides efficient leverage for breaking 2 Figure 1 Figure 3 Southern Electrical equipment Company, Inc.

8 Box 668547 Charlotte, 28266 Phone (704) 392-1396 Fax (704) 392-7033 E-Mail the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityServing the Electrical UtilityIndustry Since 1920 Industry Since 1920 Industry Since 1920 Industry Since 1920 Industry Since 1920 Document PC-002-OverviewApril 15, 20023 Proper alignment of the blade with the clip assembly (jaw) contact fingers is easilyaccomplished with the rocker bottom feature (figure 4) of the blade-hinge feature insures that the blade-end engages the contact fingers in the verticalcenter of the clip assembly. Compensation for insulator tolerances is accomplished,without using shims, by loosening and tightening two of the four bolts attaching theblade hinge assembly to the insulators. The two bolts that align parallel with thelong axis of blade are used for this adjustment, while the other two bolts are usedsolely to secure the rocker bottom to the insulator Fingers (Jaw)Contact Fingers (Jaw)Contact Fingers (Jaw)Contact Fingers (Jaw)Contact Fingers (Jaw)High-pressure, self-wiping, silver-to-copper contacts give superior conductivity with-out contact abrasion and provide ample mechanical and Electrical security to meetindustry standard high-current test requirements.

9 The four contact fingers (figure 5)are hard-drawn copper with silver button-contacts. Large contact deflection is pro-vided by separate fatigue-resistant backup springs to maintain high contact pres-sure under the extreme conditions of outdoor service. The main current path isthrough the hard-drawn copper fingers, not through the backup in-line arrangement (figure 6) of the contact fingers relative to the blade pro-vides increased contact forces when the switch is subjected to high-current contact finger and backup spring is attached to the jaw-hinge casting with twobolts, which provides a means for accurately setting contact pressure in Blade Blade Blade Blade AssemblyAssemblyAssemblyAssemblyAssembly The tubular blade is rigid, hard-drawn copper (figure 6) with a bronze guide at theblade end. The silver contact buttons engage the blade, allowing the current to passdirectly from the jaw contact to the blade.

10 Straight-line current transfer from blade toclip fingers provides the additional advantage of a blade-gripping action under highfault current Bearing Main Bearing Main Bearing Main Bearing Main Bearing AssembliesAssembliesAssembliesAssemblies AssembliesThe main bearing, which supports the rotating insulator, consists of upper and lowergreaseless ball bearing assemblies, utilizing stainless steel balls and races. Bear-ing assemblies are permanently sealed and maintenance free for the life of switches with 3-inch bolt circle insulators (ratings 15-69 kV), the bearings areassembled in high-strength aluminum housings (figure 7). The bearing housings for5-inch bolt circle switches (ratings 115-161 kV) are of galvanized steel (figure 8).The 5-inch bolt circle bearings include four leveling screws to facilitate insulatoralignment after assembly onto the 4 Figure 5 Figure 6 Figure 7 Figure 8 Southern Electrical equipment Company, Inc.