12kV Porcelain Bushing Type 3 Phases Electric Isolator Switch

12kV Porcelain Bushing Type 3 Phases Electric Isolator Switch

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 Type GN30-12Q (CT)/630, 1000 or 1250 isolating switch is a new and porcaluin bushing type rotary isolating switch. The main body of the isolating switch is fixed at two sides of a bottom frame by two groups of insulators, the two sides are fully separated from each other by an isolated plate connected at the frame. The opening and closing of the isolating switch are fulfilled by rotating the contacting knives. On the basis of the original switch, an earthing knife is added to form a GN30-12QD (CT) isolating switch to satisfy different requirements of switchgear boards. Because of the contacts seats are respectively assembled at the two sides of the isolated plate of the switch, it makes the two parts (with and without voltage) are fully separated from each other in a switchgear board, so the absolute safety for maintenance workers is guaranteed.

5.2 The conductive component consists of a moving contacting knife and a contacting seat. The contacting knife is made of two copper plate fixed in rotary porcelain bushing, and a magnetic locking plate is added to increase rigidity of the contacting knife to guarantee the dynamic and thermal stability of the switch while a short circuit trouble occurs.

5.3 Line contacting is applied for the contacting of the contacting plate and contacting seat, for decreasing the technological difficulty of assembly and warrant a good contacting.

5.4 CS6-2 operating mechanism can be used for the isolatingswitch, and the other operating mechanism self-designed is also used possibly.

6 Technical Parameters for GN30-12QD(CT) Insolating Switches

                                                  Table 1                                                                      Table 2

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

12kV Porcelain Bushing Type 3 Phases Electric Isolator Switch

12kV Porcelain Bushing Type 3 Phases Electric Isolator Switch

  12kV Porcelain Bushing Type 3 Phases Isolator Switch