Composite Shielded Fully Insulated Busbar

1. High Current-Carrying Capacity: The tubular busbar is a hollow conductor with a large surface area. Practical experience has shown that, during current flow, the current density distributed on the conductor’s surface is significantly higher than the current density at the center of the conductor. Compared to rectangular busbars, tubular busbars have a higher current density and more uniform current distribution, making them particularly suitable for applications involving high current levels.

Category:

Insulated Copper Pipe Bus

Product Description

　　1. High current-carrying capacity

　　Tubular busbars are hollow conductors with a large surface area. Practical experience has shown that, during current flow, the current density distributed on the conductor's surface is significantly higher than the current density at the center of the conductor. Compared to rectangular busbars, tubular busbars have a higher current-carrying density and a more uniform current distribution, making them better suited as carriers for high-current applications.

　　2. Good heat dissipation performance

　　Under the influence of high voltage and strong current, any conductor will inevitably experience a temperature rise during operation. However, tubular conductors, being hollow with a large surface area and excellent ventilation, allow for rapid convection and superior heat dissipation compared to rectangular conductors. In particular, copper tubular busbars, thanks to copper's excellent thermal conductivity, exhibit minimal temperature rise even under conditions of high voltage and strong current, thus offering enhanced safety.

　　3. Low skin effect and minimal power loss

　　In traditional manufacturing processes, since multiple rectangular conductors are stacked together as carriers, when current flows through these carriers, the skin-effect coefficient continuously increases under the influence of the electromagnetic field between the individual rectangular conductor sheets, leading to a significant reduction in the effective current-carrying capacity per unit cross-section. In contrast, tubular conductors, with their smooth, rounded surfaces and absence of sharp edges—and without the need for overlapping—have a skin-effect factor Kf no greater than 1, thereby avoiding the drawbacks associated with rectangular conductors.

　　4. High mechanical performance and high allowable stress

　　The allowable stress of tubular busbars is four times that of rectangular busbars, enabling them to withstand higher short-circuit currents and offering superior mechanical strength. Tubular busbars also allow for larger support spans: a Φ80×6mm tubular busbar can span up to 8 meters, while a Φ100×8mm tubular busbar can span up to 10 meters. Due to these large support spans, tubular busbars can be directly installed in high-voltage rooms, connecting either to indoor current-limiting reactors or to 10-kV and 35-kV switchgear cabinets, thereby reducing the need for supporting insulators, busbar fittings, and civil foundation structures.

　　5. Highly resistant to environmental interference and featuring a high safety factor.

　　The composite shielded busbar features a closed insulation layer with a zero-ground potential on its outer surface, offering excellent insulation performance. During the power-frequency withstand voltage test, it can withstand 105 kV/min without breakdown. In operation, it effectively prevents contact between people or objects and the ground, thereby avoiding grounding and short-circuit accidents.

　　6. Easy to install and maintain, with a long service life.

　　The main insulating materials used in insulated busbars are polytetrafluoroethylene and cross-linked polyethylene extruded over the conductor. These busbars can operate safely in environments ranging from -250°C to 250°C, exhibiting excellent electrical performance and chemical stability. They are heat-resistant, aging-resistant, and have a service life of over 40 years.

　　7. The tubular busbar bridge has a simple structure, clear layout, convenient installation, easy maintenance, and an aesthetically pleasing appearance.

　　8. Basic Performance

Project	Unit	Indicator
Resistivity at 20℃	Ω•mm²/m	0.01738
Resistance temperature coefficient at 20℃	1/°C	0.00385
Density	g/cm³	8.89
Melting point	Celsius	1083
Specific heat	J/g•℃	0.3843
Thermal conductivity	J/cm•s•℃	3.8644
Thermal linear expansion coefficient	1/°C	16.42 × 10⁻⁶
Elongation	%	≥3
Maximum allowable stress	Mpa	140
Modulus of elasticity	Mpa	100000
Allowable maximum heating temperature	Celsius	300
Tensile strength	Mpa	≥315

　　9. Data for calculation

Specifications	Carrying capacity (A)	Section modulus (cm³)	Radius of gyration (cm)	Moment of inertia (cm⁴)
Φ100×10	6000	59.04	3.2	295.2
Φ100×8	5600	50.21	3.26	251.05
Φ100×6	4200	40.03	3.33	200.15
Φ100×5	3880	34.39	3.36	171.95
Φ80×10	5400	35.00	2.50	140.00
Φ80×8	4300	30.23	2.56	120.92
Φ80×5	3060	21.19	2.66	84.76
Φ60×5	2250	11.18	1.95	33.54
Φ50×5	1840	7.38	1.60	18.45

　　10. Technical Specifications for Electrical Testing of 10 kV Insulated Busbar Systems

　　Electrical Test Technical Specifications for 11.35 kV Insulated Busbars

None

Pillar-type insulating busbar

None

Pillar-type insulating busbar

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Hubei Bailian New Energy Technology Co., Ltd. Enterprise Code

Hubei Lianhua Power Busbar Manufacturing Co., Ltd. Enterprise Code