QB27.5 single-insulation porcelain cantilever insulators
QB27.5 series 27.5kV
Specifications
| Model | QB27.5 |
|---|---|
| Standard | GB/T 11030-2008, TB/T 3199 series (Insulators for electrified railway OCS) |
| Rated Voltage | 25kVOCS systems |
| Operating Temperature | -40℃~+70℃ |
| Altitude | <4000m |
| Materials | highstrengthporcelain/composite silicone-rubber insulator, zinc-sleeve steel pin |
| Installation | cantilever, positioning and suspended installation at tensioning points |
single-insulation porcelain cantilever insulatorsis the most common OCS insulator type, for 27.5kVcantilever points of electrified railway OCS, with mechanical bending strength classes covering4kN, 8kN, 12kN, 16kN, 20kN, 25kN, to TB/T 3199.1-2018 and GB/T 11030-2008. Model designation: QB — porcelain cantilever insulator; 27.5 — rated voltage (kV); 8/12/16/20/25 — bending failing load (kN); 1200/1400/1600 — creepage distance (mm).
| Model | Rated voltage | Cantilever load | Creepage distance | Structure heightH(mm) | Arc distanceh(mm) |
|---|---|---|---|---|---|
| QB27.5/8-1200 | 27.5kV | 8kN | 1200mm | 760 | 490 |
| QB27.5/12-1200 | 27.5kV | 12kN | 1200mm | 760 | 490 |
| QB27.5/16-1200 | 27.5kV | 16kN | 1200mm | 760 | 490 |
| QB27.5/20-1200 | 27.5kV | 20kN | 1200mm | 760 | 490 |
| QB27.5/25-1200 | 27.5kV | 25kN | 1200mm | 760 | 490 |
| QB27.5/8-1400 | 27.5kV | 8kN | 1400mm | 775 | 510 |
| QB27.5/12-1400 | 27.5kV | 12kN | 1400mm | 775 | 510 |
| QB27.5/16-1400 | 27.5kV | 16kN | 1400mm | 775 | 510 |
| QB27.5/20-1400 | 27.5kV | 20kN | 1400mm | 775 | 510 |
| QB27.5/25-1400 | 27.5kV | 25kN | 1400mm | 775 | 510 |
| QB27.5/8-1600 | 27.5kV | 8kN | 1600mm | 790 | 530 |
| QB27.5/12-1600 | 27.5kV | 12kN | 1600mm | 790 | 530 |
| QB27.5/16-1600 | 27.5kV | 16kN | 1600mm | 790 | 530 |
| QB27.5/20-1600 | 27.5kV | 20kN | 1600mm | 790 | 530 |
| QB27.5/25-1600 | 27.5kV | 25kN | 1600mm | 790 | 530 |
Performance
Operating Conditions
for different pollution class sections, bearing both mechanical load and electrical insulation duties.
Mechanical Performance
Cantilever load8~20kN classcomplete, each porcelain body passes an individual mechanical load test; composite type is impact-proof without shattering.
Electrical Performance
Dry/wet power-frequency withstand voltage, lightning impulse withstand voltage and creepage distance meet TB/T 3199 — double-insulation types offer higher reliability.
Applications
Mainline cantilever suspension:
mainline cantilevers use single-insulation porcelain cantilever insulators to insulate live parts from masts.
Heavily polluted coastal sections:
large-creepage single-insulation porcelain cantilever insulators prevent pollution flashover in coastal heavily polluted sections.
Tensioning insulation:
at tensioning points, single-insulation porcelain cantilever insulators bear tension and provide insulation.
Cold regions:
single-insulation porcelain cantilever insulator bodies resist freeze-thaw cycles stably in cold regions.
