Composite Insulator - Long Rod

composite insulator

Composite insulator are also named polymer insulator, silicone rubber insulator, composite long rod insulator etc. According to how insulators are installed they can be classified as suspension type composite insulator, tension type insulator.

The complete composite insulators consist of a ECR Fiberglass Reinforced Plastic (FRP) core having superior electrical and mechanical performance, sheath (housing), sheds and metal end fittings.

Main Feature of Composite Insulators

Composite insulators are designed according to the basic insulation levels (power frequency withstand voltage, BIL & BSL etc.) as specified by customers. For installations at altitudes higher than 1000 meter, the insulation levels shall be corrected as per IEC 62271-1. The electrical withstand values shall be met with combined power arc protection devices including electric field control corona rings installed.

Mechanical and Electrical characteristics of composite insulators are the base designing requirements.

Core

The core is made of Electrical Grade Corrosion (ECR) Fiberglass Reinforced Plastics (FRP) Rod, with acid and high temperature resistance performance.

To reduce the risk of brittle fracture, the FRP core of composite insulators will be electrical corrosion-resistant (ECR) glass rod that shall achieve the specified electrical and mechanical characteristics. The FRP core will be resistant against hydrolysis under service conditions.

Housing

Housing (sheath and weather sheds) is made of high temperature vulcanized (HTV) silicone rubber, which has excellent hydrophobicity and ant-tracking performance. The composite insulators have hydrophobicity of silicone rubber material classified Hydrophobicity Class 1 (HC-1) . or it can be described as receding water contact angle will be 80° or more.

The composite insulators sheath and sheds material have a chemical structure of 100 percent silicone rubber before adding fillers. The finished product will be ultraviolet (UV) radiation exposure resistant. The finished product shall not be affected by atmospheric conditions due to weather, proximity to the coast, fumes, ozone, acids (particularly sulfuric acid present in the prevailing environment of oil field areas in the region), alkalis, dust or rapid changes to air temperature. There shall be no material degradation such as development of surface cracks and increase in surface hardness, etc.

The track resistance of the sheath and shed material shall meet the requirements of IEC 60587 Method 1 Class 1A4.5 or 1B4.5 or Method 2 Class 2A4.5.

The sheath and sheds material of insulators fabricated from high temperature vulcanized silicone rubber shall have a Shore ‘A’ hardness of not less than 60.

The composite suspension and tension insulators shall be of alternating shed design with aerodynamic type profile and without any under-ribs designed in accordance with IEC/TS 60815-3. Sheds shall be at intervals to provide optimum electrical performance and the shed design shall provide a protected bottom surface that tends to keep dry in wet conditions. In accordance with IEC/TS 60815-3, the shed spacing (defined as the minimum vertical distance between two similar points of successive sheds of the same diameter) and the ratio of shed spacing to shed overhang/projection shall be more than 40 mm and 0.80 respectively.

Top end-fitting, Bottom end-fitting

End-fittings are made by forged steel or ductile cast iron (treaded with hot dip galvanizing). end-fittings are fastened to the core by precise crimping method.Metal parts are made of the best commercial grade of malleable iron, ductile iron or steel, and galvanized in accordance with the Specification.

Interface

Housing is firmly bonded to core by high performance bonding agent to protect the core from getting damaged by acid, water, alkali and UV rays etc.

End-fittings have special sealing groves and filled by HTV silicone rubber during molding injection, which will prove excellent sealing properties.

Technical Data

Nominal
System
Voltage
(kV)
Model Section
Length
(mm)
Nominal
Creepage
Distance
(mm)
Min. Dry
Arcing
Distance
(mm)
Power Frequency (kV) Lightning Impulse (kV)
Withstand Voltage Flashover Voltage Withstand Voltage Flashover Voltage
Dry Wet Dry Wet + - + -
66 - 69 LR-120SB-860-1160 860 1160 620 190 180 240 220 320 350 390 410
LR-120SB-955-1450 955 1450 715 260 240 275 250 380 410 400 420
LR-120SB-955-1813 955 1813 715 260 240 275 250 380 410 400 420
LR-120SB-980-2248 980 2248 740 265 245 285 260 385 415 480 500
LR-120SB-1060-2900 1060 2900 820 300 280 340 310 470 510 530 550
110-150 LR-120SB-1240-2540 1240 2540 1000 355 325 380 342 560 610 625 650
LR-120SB-1240-3175 1240 3175 1000 355 325 380 342 560 610 625 650
LR-120SB-1320-3940 1320 3940 1080 380 350 410 370 610 650 670 690
LR-120SB-1340-2900 1340 2900 1100 385 355 420 380 615 650 680 700
LR-120SB-1460-3625 1460 3625 1220 420 390 460 410 690 730 740 760
LR-120SB-1600-4495 1600 4495 1360 440 400 510 460 750 790 820 870
LR-120SB-1640-5800 1640 5800 1400 475 435 530 470 785 830 850 900
LR-120SB-1606-3080 1606 3080 1366 440 400 515 465 750 800 825 875
LR-120SB-1606-5184 1606 5184 1366 420 400 515 465 750 800 825 875
220-230 LR-120SB-2160-4900 2160 4900 1920 585 565 720 648 1095 1120 1140 1190
LR-120SB-2160-6125 2160 6125 1920 585 565 720 648 1095 1120 1140 1190
LR-120SB-2300-7595 2300 7595 2060 600 580 760 680 1120 1160 1220 1250
LR-120SB-2400-8575 2400 8575 2160 630 600 810 720 1175 1200 1280 1340
LR-120SB-2700-9800 2700 9800 2460 690 660 910 820 1330 1360 1440 1500
330 LR-120SB-2780-7260 2780 7260 2540 700 670 950 850 1370 1420 1460 1510
LR-120SB-2780-9100 2780 9100 2540 700 670 950 850 1370 1420 1460 1510
400-500 LR-120SB-3350-8400 3350 8400 3100 800 770 1100 960 1680 1710 1850 1900
LR-120SB-3380-10500 3380 10500 3130 810 780 1120 980 1690 1720 1870 1920
LR-120SB-3380-13020 3380 13020 3130 810 780 1120 980 1690 1720 1870 1920
LR-120SB-4050-11000 4050 11000 3800 910 870 1310 1110 2000 2050 2260 2310
LR-120SB-4050-13750 4050 13750 3800 910 870 1310 1110 2000 2050 2260 2310
LR-120SB-4300-17050 4300 17050 4050 955 915 1380 1180 2180 2230 2350 2400