When a steel mill in northern China needed to modernise the electrification of a 40 t ladle crane, the engineering team chose a 2,500 A cast-resin busbar system instead of replacing the existing cable festoon.

The crane operates continuously in a casting bay where ambient temperature regularly exceeds 60 °C and radiant heat from the ladle adds a further load. The original festoon system suffered repeated cable failures, each of which stopped the casting sequence and required a manned intervention in a high-temperature area.

Why cast-resin busbar

Cast-resin busbar uses a solid epoxy insulation that is cast around the conductors. It has no air gap, so it resists dust and moisture ingress, and the insulation withstands continuous high temperature far better than a flexible cable sheath. The customer selected a 2,500 A bus duct with an IP68 protection class and a low smoke, halogen-free formulation.

• Rated current: 2,500 A, four conductors plus PE
• Protection: IP68, halogen-free cast resin
• Ambient: continuous 60 °C with short-term radiant peaks
• Length: 96 m of straight runs with 6 expansion and 4 angle sections

The bus duct has no moving parts and no flexible cables to replace in the hot zone, which is exactly what the maintenance department asked for.

The upgrade was carried out over a planned five-day shutdown. After twelve months in service, the system has recorded no unplanned stoppages related to electrification, and maintenance in the high-temperature zone has been reduced to periodic visual inspection.