Working Principle and Selection Guidelines for Cable Bus Bar Systems

While cables are widely recognized as essential components in industrial and high-current applications, cable bus bar systems — also referred to as cable trolleys or conductor rails — are specialized solutions for mobile power transmission. These systems play a critical role in supplying power and signal transmission to cranes, hoists, and other moving equipment in ports, railway yards, and industrial facilities.

Working Principle of Cable Bus Bar Systems

A cable bus bar system comprises three primary components:

1. Flat Cable – Constructed from flame-retardant materials suitable for indoor, outdoor, and oily environments. Compared to round cables, flat cables offer a smaller bending radius and longer service life.
2. Cable Trolley (Four-wheel Carriage) – Supports and guides the flat cable along the track during movement.
3. Bus Bar / Guide Rail – Fabricated from cold-rolled steel using a single cold-drawing process to ensure dimensional accuracy. Rail sections are typically supplied in 4–6 m lengths and can be joined using couplers for extended runs.

This engineered design replaces older methods such as angle-iron conductors, eliminating risks like dust accumulation indoors or ice formation outdoors, which could lead to short circuits and operational failures.

Installation Method

The flat cable is anchored at the starting point near the electrical junction box. At intervals of 1–2.5 meters, the cable is attached to trolleys that travel along the bus bar. The opposite end of the cable is connected to the final trolley (the tractor unit). A spring-driven mechanism enables smooth to-and-fro motion, allowing all trolleys to glide freely along the rail at variable speeds without sparking or contact wear. Installation is straightforward and requires no complex adjustment.

Key Selection Considerations

Tractor trolley assembly (1 set)

Rail Length
Determine based on the actual travel distance of the crane or moving equipment, plus extra length for trolley parking.

Cable Length
Total length = travel distance + trolley storage allowance + additional run to electrical panels or devices.

Number of Trolleys
Typically equal to half of the rail length in meters. Can be adjusted based on allowed cable sag and span conditions.

Coupler Quantity
Required when the total bus bar length exceeds the standard single section (4–6 m).

Accessories (Per Traveling Unit)

End stop (1 pc)

Cable anchor clamp at starting end (1 pc)

Maintenance and Operational Guidance

Due to their continuous movement, cable bus bar systems are susceptible to jacket abrasion and environmental exposure, which may shorten service life. Regular cleaning, inspection, and preventive maintenance are essential to maximize longevity and reduce lifecycle costs. As these systems are often custom-engineered, users are advised to define their operational and environmental requirements clearly before ordering.

This guide aims to enhance understanding of cable bus bar systems to support proper selection, installation, and sustainable operation in demanding industrial applications.