Post Insulator

Technical Advantages

Simplified Structure and Easy Installation： The insulated tubular bus bar is directly fixed to steel structures or concrete supports, eliminating the need for wall bushings and post insulators. It adopts an exposed installation method, supported by dedicated tubular bus bar brackets with a spacing of ≥275 mm. Fixed brackets are installed when the span ranges from 6 m to 13 m.

High Mechanical Strength and Large Support Span： The allowable stress of the insulated tubular bus bar is four times that of rectangular bus bars, enabling it to withstand significant short-circuit currents. Under a short-circuit current of 50 kA, a Φ100×6 mm tubular bus bar achieves a suspended span of up to 9 meters, and with bus bar bracket support, the span can reach 13 meters. The bus bar can be directly connected to high-voltage chambers, indoor current-limiting reactors, or 10 kV switchgear cabinets, reducing the need for corresponding post insulators, bus bar fittings, and structural foundations.

Strong Seismic Performance： The product design considers seismic conditions, withstanding horizontal acceleration of 0.20 g, vertical acceleration of 0.15 g, vibration frequency of 20 Hz, and tolerance to three sine wave cycles. The safety factor exceeds 1.67, ensuring normal operation under simultaneous seismic and short-circuit conditions.

Excellent Environmental Adaptability： Suitable for altitudes ≤4000 meters and environments with pollution severity class V (heavy pollution), the design creepage distance ratio is 31 mm/kV. After installing creepage extenders on outdoor terminals, the total creepage distance is not less than 680 mm.

Features

Value of Structural Simplification
In traditional busbar systems, post insulators serve the dual functions of mechanical support and electrical insulation. Through innovative designs that directly fix tubular bus bars onto steel structural supports, the number of insulators used is not only reduced, but the system structure is fundamentally simplified. This lowers installation complexity and potential failure points, reflecting the technological trend of evolving from discrete components toward integrated systems.

Environmental Adaptability Requirements
Post insulators must meet long-term stable operation requirements in harsh environments, particularly under severe conditions with pollution levels up to Class V, where their anti-pollution flashover performance becomes a critical indicator. By optimizing the shed design, using hydrophobic materials, and strictly controlling the creepage distance, reliable insulation performance is ensured in special environments such as coastal and industrial pollution areas.

Comparative Analysis of Installation and Maintenance
Compared to the complex procedures required for installing traditional post insulators—such as foundation construction,  leveling alignment, and multi-point fixation—integrated tubular bus bar systems adopt standardized bracket installation methods, significantly shortening construction periods. In terms of maintenance, traditional insulators require regular contamination cleaning, crack detection, and electrical testing, whereas the fully enclosed design of tubular bus bars substantially reduces maintenance frequency and costs.

Material and Process Technical Characteristics
Modern post insulators are primarily manufactured using high-strength electrical porcelain, toughened glass, or composite materials. Among these, composite insulators offer advantages such as excellent hydrophobicity, high burst resistance, and light weight.