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Brush plating eliminates component removal

Issue 7 and Volume 102.

Brush plating eliminates component removal

The Stanton Steam Power Plant in Orlando, Fla., recently upgraded a bus duct system with silver plating to prevent oxidation. Stanton management found that brush plating could help efficiently complete the retrofit work and avoid long generator down time.

Bus duct systems are high amperage primary output conductors that are cooled by air forced through a shroud surrounding the bus bars. One of the project`s requirements was plating the mating surfaces of the bus connectors with 0.0005 inches of silver to prevent oxidation that leads to increased electrical contact resistance and excessive heat at the connection.

On the Stanton job, the bus components were constructed of 6101 alloy aluminum extruded flat bars. The only areas that required plating on this part of the system measured 6 to 8 inches square and were located on the ends of the components.

Normally, the components would be tank plated using a cyanide silver bath to apply the deposit. This would require that the fabricated components be hoisted by a crane, then dipped into a series of tanks for coating. Calvert Co. of Richland, Miss. conducted the retrofit work using a portable brush plating system manufactured by SIFCO Selective Plating of Cleveland, Ohio. The process requires very small volumes of plating solution, takes up little space, and can be used on site.

Other bus duct system components at Stanton that required silver plating included custom fabricated primary output conductors, a dozen 3.5×4 inch flat areas, and the faces of a dozen flexible braided conductors. These parts were also plated in place.

Brush plating in thicknesses less than 0.001 inch is typically accomplished in five minutes or less per area. Brush plating reduces downtime by eliminating the need for component disassembly and removal for shipment to a plating shop.

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