Rectangular busbars

Figure 28.13(a) Skin effect in isolated rectangular busbars, (neglecting the proximity effect) (Courtesy l ndian Aluminium Co, based Alcon of Canada)... 

Figure 28.19(a) Reactance of rectangular busbars at 50 Hz on account of proximity effect... 

Assume the temperature of the busbars at the time of fault = 85°C and rectangular flats of electrolytic grade E-91E or its equivalent. Busbars chosen for each phase - four (152.4 mm X 6.35 mm) - which are more than the minimum size required to account for the thermal effects during a short circuit condition... 

For the rest of the calculations for mechanical suitability of the busbar system the procedure for rectangular sections can be followed. 

In a typical electrowinning or electrorefining operation, the electrolytic cells are rectangular tanks, and each contains 20-50 electrode pairs. An additional anode is required in each cell to ensure deposition on both sides of each cathode. The electrodes are designed to rest on busbars that supply electricity. The busbars are situated outside the top of each tank, one for the anodes and another for the cathodes. Thus, the electrode pairs in each tank operate in parallel. In the tankhouse, the cells are arranged in sections with the banks of cells connected in series and parallel to obtain optimum use of the electrical power, while keeping the voltage to earth at any point at a low level that is not a risk to the personnel. 

Buswork Arrangement. This section will give the reader a feel for the size of the conductors required for safe handling of the cell-room current. In smaller plants, particularly in those based on bipolar electrolyzers, cables of the proper diameter can serve as conductors. Most plants use a multiplicity of bars with rectangular cross-section operating in parallel, and the following discussion is in terms of such busbars. 

Main Bus. The MCC should be bused with rectangular busbars made of tin... 

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