Switchgear High Voltage Disconnect Knife Switches

Switchgear High Voltage Disconnect Knife Switches

1. Application

1) For the disconnecting switches, they are a key component of metal enclosed switchgear. These switches are suitable for service in a 12kV 50Hz AC 3-phase power system.

2) For the earthing switches, they can be accompanied with varieties of high voltage switchgears and used for earthing while maintenance of high voltage equipment.

2. Technical parameters

1).Rated Voltage: up to 12 kV

2).Rated Current: up to 4000A

3).Thermal Current for 4s (r.m.s): up to 40 kA

4).Dynamic Current (peak): up to 125kA

5).Rated Frequency: 50Hz

6).Material: porcelain

*Except for the parameters listed above, we can design as per clients’ requirements.

3. Main features

1) For the disconnecting switches:

A. Every phase conductive body for an isolating switch of series GN19-12Q is fixed on a bottom seat by two post insulators. (There are C1, C2 and C3 three gone-thru types for GN19-12C isolating switch, C1, C2-a post insulator and a bushing at one side respectively; C3-two sides are all bushings). The conductive body for every phase is composed of a contacting knife and a stationary contact. At the mid of every contacting knife is connected with a pull rod insulator that is connected with a main shaft mounted on a bottom frame by a connecting rod. The main shaft is connected to CS6-1T operating mechanism by a crank arm and connecting rod. The mechanism is connected to the isolating switch by a connecting rod supplied by customers to make the relative movement of the mechanism and the switch.

B. For GN19-12Q/1000 (1250) and GN19-12CQ/1000(1250) isolating switch, there is a magnetic locking pressing plate mounted at the contacting place. So, the attraction force between two groove contacting knives, the contacting pressure at contacting place and the dynamic and thermal stability for the switch are all enhanced while a short circuit current flows. A bottom frame assembly consists of bottom frame, main shaft and an arrester, the arrester guarantees the final position demanded while the conductive contacting knife “opening” and “closing”.

2) For the earthing switches:

A. Consisting of a bracket, a contacting knife, insulators, a closing spring and contacting seat.

B. When the process of closing, an action torque coming from the operating mechanism makes the main shaft 6 overcome a resistance torque and rotate the operating plate 4 at the direction of closing, and make a swing rod on the mobile knife 1 run over the spring dead center, and the spring releases energy to make the earthing switch accelerate closing.The tight and reliable contacting by butterfly spring 5 on the mobile knife 1 of the knife of the stationary contact 3 and contacting knife reaches the earthing demand. While opening, an action torque makes the main shaft 6 overcome a resistance torque and spring force, rotate the operating plate 4 at the opening direction, and make the swing rod on the mobile knife 1 compress the spring 2 to the dead center, and the energy storage ends for next closing.

4. Manufacturing standards: IEC62271-102:2002, GB1985-2004

5.  Features of Main Structure:

5.1 Functions of isolating switch and earthing switch are realized by one driving shaff and one movable contact knife in the condition of air insulation. The product is a new multi-function switch that owns three operation positions of on, isolating (off) and earthing.

5.2 The structure of products is reasonable, copact, smsall volume, safety and reliable. The performance of anti-wrong-operation is quite good. It is an ideal matched product of minimized switchgear.

5.3 When on and off operation, turn a crank connecting to a shaft by an operating handle, a connection rod make a movable contact knife rotate for closing, isolating(testing) and earthing.

6.  Technical Parameters for GN-12Q/1250 Insolating Switches

Technical Parameters Table

Notes: Detailed technical data and outline drawings shall be provided upon request.