U40B Glass Insulator CTV175 for HVDC Overhead Transmission Line

Product Overview

● Model: U40B

• U Refers To Disc Suspension Insulator

• B For Ball And Socket Type

● Type: Standard Profile Toughened Suspension Type

● Rated mechanical load: 40kn (about 4 tons)

● Purpose: Glass insulator U40 is mainly used in overhead transmission lines with voltage levels of 35kV and below for insulation and suspension wires. It is widely used in urban power grid, rural power grid and power supply lines of some industrial enterprises. It can effectively isolate the wire from the ground body such as the pole and tower, ensure that the current is transmitted along the wire, prevent the current from leaking to the ground, and ensure personal safety and the normal operation of the power equipment.

● The product model is in accordance with GB/T 7253-2005 and JB/T9683-2012(EC60305:1995MOD)

● The connection structure is in accordance with GB/T4056-2008(IEC60120:1984,MOD) and BS 3288 part lll. 

● According to customer requirements, the locking pin can be either W-pin or R-pin.

●  lf there is no special instruction, R pin is used for U40B.

Structure and materials

• Glass umbrella tray

  • Electrical performance: With good insulation performance, can withstand high voltage, power frequency wet withstand voltage of up to 25kV, lightning impulse withstand voltage of 50kV, power frequency breakdown voltage of 90kV, can effectively prevent current leakage and flashover, ensure the safety of power transmission.

  • Mechanical properties: The mechanical failure load is 40kN, and the tensile load test value is 20kN one by one, which can withstand a certain tension and pressure, and adapt to the operation requirements of overhead transmission lines.

  • Aging resistance:The glass material has good stability, is not easy to age, can maintain good electrical and mechanical properties for a long time, and has long service life.

  • Zero self-detonation characteristics: the glass insulator has zero self-detonation characteristics. When the insulator loses its insulation performance with zero value, the umbrella skirt will burst automatically, which is convenient for operation and maintenance personnel to find and replace in time, and reduce the risk of line operation.

• Metal accessories

  • Cap&foot: Made of iron or steel and treated with corrosion resistance, such as galvanizing to improve corrosion resistance in harsh environments. The main function of the steel cap is to connect with the pole or other metal appliances to realize the connection between the insulator and the support structure of the transmission line. Steel feet are used to connect wires.

  • Locking pin: The locking pin is divided into W pin and R pin, which is an important part to ensure the reliability of insulator series.

• Umbrella skirt design

  • The umbrella-shaped design makes the electric field distribution on the insulator surface more uniform. Due to the existence of the umbrella skirt, the distribution of electric field lines on the insulator surface is no longer uniform and straight, but bends and diffuses along the shape of the umbrella skirt. This can avoid the electric field concentrated in some local areas of the insulator, reducing the occurrence of partial discharge and corona phenomenon.

  • The umbrella structure makes the surface of the insulator form a concave and convex shape, which increases the creepage distance of the insulator compared with the flat design. Under the same insulator height, the increase in creepage distance means that the insulator can withstand higher voltage without flashover phenomenon, improve the insulation performance of the insulator, and ensure that good insulation performance can be maintained in harsh electrical environments, such as wet, dirty and other conditions.

key parameters