High Voltage Disconnector SwitchHV AC SwitchgearVideos

High voltage horizontal center break two column disconnector switch

 

 

 

 

 

This disconnector type is used for rated voltages of 36 to 525 kV in substations.
As shown in movie, the two rotating bases are mounted on a sectional steel frame and connected by a braced tie-rod. The insulators (post insulators) are fixed to the rotating bases and carry the swivel heads with the arms and the high-voltage contacts.
Both arms swivel 90 degrees with their insulators during the switching movement.

Two column rotary disconnectors in their open position form a horizontal isolating distance.
The rotary bases are weather protected and have maintenance-free ball bearings. The rotary bases are fastened on stay bolts, which allow precise adjustment of the contact system after the lines have been rigged and also compensate the insulator tolerances.
This type of disconnector switch can be equipped with right or left or both side earthing switch.

The swivel arms are an aluminium-welded construction with non-corroding contact joints, thereby eliminating any long-term changes in resistance. Disconnectors 170 kV have an interlocking mechanism (pawl and pin). This prevents the contacts from opening at high short-circuit currents. The current in the maintenance-free swivel
heads, which are protected against external influences, is transferred via contact fingers arranged in a tulip shape around two contact pins, or for operating currents > 2500 A via tapered roller contacts. The high-voltage contacts can be rotated 360 degrees, allowing the tube or wire runs to be connected in any direction. The contact
system has separately sprung contact fingers with no exposed springs.
The disconnectors and earthing switches have an operating mechanism with dead centre interlocking. This prevents its position from being changed by extreme external influences, such as short circuits, earthquake or high winds. Disconnectors and earthing switches have separate mechanisms. For rated voltages of up to 300 kV, a three-pole disconnector or earthing switch group is generally actuated with one mechanism each. The individual poles of one group are mechanically linked by a connecting rod. The torque is transferred by the mechanism to a rotating base and rotates it by 90 degrees. The tie-rod rotates the second rotating base simultaneously.
The contacts make both a rotary and a sliding movement when opening and closing the disconnector. This easily breaks heavy icing. The torque of the earthing switch is transferred to the shaft of the earthing switch. On closing, the arm of the earthing switch swivels upwards and meets the earthing contact attached to the swivel arm.

Disconnectors and earthing switches have separate mechanisms.
The contacts make both a rotary and a sliding movement when opening and closing the disconnector.

Advertisement
Source
ABB switchgear pocket book 10 th edition
Tags

Leave a Reply

Your email address will not be published. Required fields are marked *

Back to top button
Close
Close