QBS27.5 double-insulation porcelain cantilever insulators
QBS27.5 series 27.5kV
Specifications
| Model | QBS27.5 |
|---|---|
| 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 |
The QBS27.5 double-insulation porcelain cantilever insulator series suits cantilever points of 27.5kV electrified railway OCS; S in the model denotes double insulation for higher reliability, to TB/T 3199.1-2018 and GB/T 11030-2008.

| Model | Rated voltage | Cantilever load | Creepage distance | Structure heightH(mm) |
|---|---|---|---|---|
| QBS27.5/8-1200 | 27.5kV | 8kN | 1200mm | 850 |
| QBS27.5/12-1200 | 27.5kV | 12kN | 1200mm | 850 |
| QBS27.5/16-1200 | 27.5kV | 16kN | 1200mm | 850 |
| QBS27.5/20-1200 | 27.5kV | 20kN | 1200mm | 850 |
| QBS27.5/25-1200 | 27.5kV | 25kN | 1200mm | 850 |
| QBS27.5/8-1400 | 27.5kV | 8kN | 1400mm | 865 |
| QBS27.5/12-1400 | 27.5kV | 12kN | 1400mm | 865 |
| QBS27.5/16-1400 | 27.5kV | 16kN | 1400mm | 865 |
| QBS27.5/20-1400 | 27.5kV | 20kN | 1400mm | 865 |
| QBS27.5/25-1400 | 27.5kV | 25kN | 1400mm | 865 |
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 double-insulation porcelain cantilever insulators to insulate live parts from masts.
Heavily polluted coastal sections:
large-creepage double-insulation porcelain cantilever insulators prevent pollution flashover in coastal heavily polluted sections.
Tensioning insulation:
at tensioning points, double-insulation porcelain cantilever insulators bear tension and provide insulation.
Cold regions:
double-insulation porcelain cantilever insulator bodies resist freeze-thaw cycles stably in cold regions.


