Post Insulator
Post insulators are widely used in low to high voltage systems, for different application, there are line post insulators and station post insulators.
Line post insulators are mounted on the electrical pole for the transmission line. According to the usage and the position it installed on the pole, the line post insulators are divided into several types: Tie Top Line Post Insulators, Horizontal and Vertical Line Post Insulators, Under Arm Line Post Insulators and Clamp Top Line Post insulators.
Station post insulators provide insulating and structural support for power plants, transmission and distribution substations, and other power facilities up to 1100kV.
Post insulators can be made of porcelain and silicone polymer. They are designed for the different markets and manufactured to standard dimensions, so they can meet the electrical and mechanical requirements of IEC, ANSI standards or customer specifications.
Porcelain post insulator
ANSI Class | 57-1 | 57-2 | 57-3 | 57-4 | 57-5 | |
Creepage distance,mm | 356 | 559 | 737 | 1015 | 1145 | |
Dry arching distance | 165 | 241 | 311 | 368 | 438 | |
Cantilever Strength,Kn | 12.5 | 12.5 | 12.5 | 12.5 | 12.5 | |
Lower Frequency Flashover Voltage | Dry,kv | 80 | 110 | 125 | 150 | 175 |
Wet,kv | 60 | 85 | 100 | 125 | 150 | |
Critical Impulse Flashover Voltage | Pos.,kv | 130 | 180 | 210 | 255 | 290 |
Neg.,kv | 155 | 205 | 260 | 340 | 380 | |
RIV Data | Test volt. To ground,kv | 15 | 22 | 30 | 44 | 44 |
Max RIV at 1000 KHz,Uv | 100 | 100 | 200 | 200 | 200 |
polymer post insulator
Type | No. Of Sheds | “X” Length inches (mm) | Diameter Inches (mm) | Leakage Distance Inches (mm) | Dry Arc Distance inches (mm) | Lighting withstand voltage | Wet power frequency voltage | End fitting diameter |
D/d | ||||||||
FZSW-12/4.0 | 4 | 254 | 120/90 | 400 | 145 | 95 | 40 | 76 |
FZSW-20/4.0 | 6 | 315 | 137/110 | 580 | 215 | 145 | 50 | 76 |
FZSW-24/4.0 | 7 | 370 | 120/90 | 580 | 260 | 145 | 50 | 76 |
FZSW-36/12.0 | 19 | 550 | 140/110 | 1260 | 404 | 230 | 95 | 140 |
FZSW-40.5/4.0 | 15 | 560 | 123/80 | 1050 | 450 | 230 | 95 | 76 |
FZSW-66/10.0 | 21 | 905 | 166/136 | 1900 | 766 | 410 | 185 | 127 |
What is post insulator?
Post insulator is a type of electrical insulator suitable for higher voltage applications, it can be made of Polymer or Porcelain.
What are the applications of post insulators?
The post insulator can be used in the transmission lines, distribution plants, and switchgear systems up to 1100 kV.
Features of post insulators
- Good creepage distance
- 1 to 1100 KV
- Severial insulators can be connected for higher voltage application