MindCore
ALUMINUM EHV VERTICAL
BREAK DISCONNECT SWITCH
400 kV. TO 800 kV.
2000 TO 4000 AMP
SV2
• Aluminum current carrying parts.
• Silver-to-silver, hi-pressure, wiping contacts.
• Substantial overload capacity.
• Momentary rating of 160K amps.
• Low radio noise & high corona extinction levels.
• Rigid tubular stand.
• Integrated design of switch and stand.
• Unique electrostatic grading system.
• Low torque, control stack.
• Fully controlled and precisely counterbal- anced blade.
• Low operating effort.
• High Mechanical advantage for making contact and breaking ice.
• Self-locking mechanism in both open and closed positions.
• Corrosion resistant bearings, lubricated for life.
• Proven in service.
The type SV2 switch is primarily intended for EHV
(Extra High Voltage) substations for isolating, bypassing or sectionalizing. It can be mounted only in a horizontal upright position.
1845 JEAN-MONNET, TERREBONNE QC J6X 4L7 TEL.: 450.477.5959
FAX : 450-477.2220
www.mindcoretech.com

MindCore
ALUMINUM EHV VERTICAL
BREAK DISCONNECT SWITCH
400 kV. TO 800 kV.
2000 TO 4000 AMP
SV2
CONTACTS
Silver-to-silver, high pressure, reverse loop female contacts provide maximum dependability under normal and short circuit conditions.
At the hinge end, current transfer, from the blade to the switch frame, is obtained in a similar manner. The silvered male contact rotates into silvered female contacts of hard drawn copper which are backed by stainless steel compression springs.
The jaw contact assembly employs contacts of reverse loop configuration which exploit the magnetic effect of increasing current to increase the contact pressure during short circuit conditions. Normal contact is maintained by insulated, stainless steel compression springs located inside the loop formed by the contact fingers and the contact housing. The contact fingers are of high conductivity hard drawn copper bar and the housing is a high conductivity aluminum alloy casting.
BLADE OPERATING MECHANISM
The rotating insulator stack drives a 18:1 gear reducer housed in the switch frame. The output shaft then drives a robust steel crank arm through 210 degrees.
The crankarm is swivel connected to the blade fork lever and lastly to the blade lever which forms part of the blade. Subsequently, rotation of the end insulator stack causes the blade to raise, lower and rotate.
1845 JEAN-MONNET, TERREBONNE QC J6X 4L7 TEL.: 450.477.5959
FAX : 450-477.2220
www.mindcoretech.com

MindCore
ALUMINUM EHV VERTICAL
BREAK DISCONNECT SWITCH
400 kV. TO 800 kV.
2000 TO 4000 AMP
SV2
The switch mechanism is designed to provide a high mechanical advantage for closing into, or opening out of, the contacts. The blade velocity, on closing, is initially high, reducing to a low velocity as it reaches the insulated stop. The blade contacts enter the jaw edgewise, then the blade rotates 90 degrees to make contact, thus assuring positive entrance of the blade even when the contacts are heavily iced. This feature, coupled with the high mechanical advantage, accounts, in part, for the low operating effort of the SV2.
that the spring force exerted on the blade follows a sine curve exactly matching the blade moment. The springs are enclosed in an aluminum housing which completely protects them from the weather. A small drain hole is provided in a protected location at the bottom to allow for the drainage of any condensation.
The stainless steel connecting rod inside the spring’s slides in an oil impregnated bronze bearing pressed into the end of the spring housing.
TERMINAL PADS
The rotation of the switch blade is controlled by compression springs located in the fork lever at the hinge end. This assures positive rotation into and out of the jaws. The hinge pin is stainless steel and rotates inside oil impregnated bronze bearing pressed into the switch frame.
The terminal pads at the jaw end are welded directly to the current carrying grading ring. This provides a current path with a minimum of transfer points. At the hinge end, the terminal pad is securely bolted to the switch frame. To prevent corona and radio interference, both terminal pads are located entirely inside of the grading rings. Almost any connector mounting arrangements can be accommodated by these large terminal pads.
The gear reducer forms an integral part of the operating mechanism. The torque on the rotating stack, in vertical break switches, appears as a cantilever force at the top of the fixed stack. Since the rotating stack is on the input side of the 18:1 gear reducer instead of the output side, this cantilever force is greatly reduced.
The result is a smaller, lower cost, rotating stack, lower forces with less deflection and vibration during operation of the main stack which supports the blade. The blade is counterbalanced by twin sets of steel compression springs which apply a force to the blade in such a manner
1845 JEAN-MONNET, TERREBONNE QC J6X 4L7 TEL.: 450.477.5959
FAX : 450-477.2220
www.mindcoretech.com

MindCore
ALUMINUM EHV VERTICAL
BREAK DISCONNECT SWITCH
400 kV. TO 800 kV.
2000 TO 4000 AMP
INSULATORS
The SV2 switch is designed for use with post type insulators. The jaw stack and the main hinge stack are identical while the rotating stack is smaller.
BEARINGS
The bearing assembly supporting the rotating insulator stack has two, large, tapered roller bearings in a weather-sealed aluminum alloy housing. A low temperature Microgel grease is used, together with a corrosion inhibitor.
OPERATING CONTROLS
Gang operation of three single pole switches, by mechanical means, is ordinarily possible, unless the phase spacing becomes too large. A torsional, interphase pipe is used in place of the reciprocating mechanism common to lower voltage type switches.
This form of drive eliminates the bracing between poles. For gang operation, the conventional switch bearing at the base of the rotating stack is replaced with a combination bearing and mitre gear box. The preferred arrangement is to drive up into the bottom of the gear box of the centre phase and then drive horizontally to the two outer phases. The operating energy may be supplied either manually or by motor mechanism. For manual operation, a 24”
(610mm) diameter handwheel is provided. When the phase spacing is very large, gang operation by electrical means is preferred. Each pole has its own motor mechanism. The control circuitry is arranged to actuate all motors simultaneously and the control switches are adjusted so that all three poles must be open before signals are given to the control room or electrical interlocks are actuated.
MOTOR MECHANISMS
Motor mechanisms are available for either AC or
DC operation in a wide range of voltages. A standard motor mechanism consists of a ½ h.p. motor driving a 200:1 gear reduction unit mounted in the upper part of the cabinet. An auxiliary switch, with
SV2 two stages as limit controls for the motor, may have up to twelve additional stages for signaling, interlocking, etc. Each mechanism housing is aluminum to prevent corrosion and is fitted with two removable doors with tight fitting gasket seals. A breather is provided to allow circulation and a heater prevents condensation.
DIELECTRIC GRADING SYSTEM
The SV2 switch has a unique grading system which effectively controls the voltage of the insulator stacks by reducing the gradient on the top unit and distributing the voltage more uniformly over the stack. On the higher voltage switches, the dual grading rings on the jaw end, give the jaw end of the switch a capacitance approximating that of the hinge end. In so doing, the gap flashover is essentially the same with either end grounded. This feature has the effect of reducing the open gap dimension for any given switching surge requirement.
In addition, the grading system effectively shields the mechanism, preventing corona and radio interference even at potentials well above the rated voltage.
SWITCH DIMENSIONS
The dimensions of EHV switches, 500kV. and above, may differ widely from one system to another. At these ratings, the switching surge withstand voltage becomes the dominant factor in determining the amount of switch insulation and the size of the gap. Since the parameters of the system will vary, it is frequently necessary to design the switch to suit the specific system.
The dimensions given on the following pages may be considered as typical only. Given the characteristics of a system, our engineers will design a suitable switch.
1845 JEAN-MONNET, TERREBONNE QC J6X 4L7 TEL.: 450.477.5959
FAX : 450-477.2220
www.mindcoretech.com

MindCore
ALUMINUM EHV VERTICAL
BREAK DISCONNECT SWITCH
400 kV. TO 800 kV.
2000 TO 4000 AMP
SV2
GROUND SWITCH
SWITCH STAND
A three pole type GSV ground switch may be fitted to either end of the SV2. This switch features high momentary, high pressure contacts and aluminum blade.
FIELD ADJUSTMENTS
SV2 switches may come complete with a tubular steel support stand for each switch phase. (Similar to shown above). Stands are custom made to suit customer’s site requirements.
To the user, the cost of a switch includes erection and adjustment.
MindCore Technologies
has done everything possible to make the work simple and time saving.
Of particular interest, the SV2 blade is factory adjusted, set, match marked and disassembled from the hinge end for shipping. This eliminates the danger of the hinge and blade jack knifing.
Alternately, SV2 switches may be mounted on a specially designed switch base, similar to smaller switches, for directly mounting on a customer’s support structure or stands.
1845 JEAN-MONNET, TERREBONNE QC J6X 4L7 TEL.: 450.477.5959
FAX : 450-477.2220
www.mindcoretech.com