Upgrading bus bracing in low voltage motor control centers

Low-voltage motor control centers (LVMCCs) built prior to the 1980s may have inadequate bus bracing. Unit substations are being expanded in order to meet the demands of an expanding electrical distribution system. The electrical system requirements in many pulp and paper mills are being enlarged with greater kVA capacity transformers. Consequently, the available RMS symmetrical fault currents are likely to be in excess of the original bus bracing rating for the LVMCC. A reliable and cost-effective means of upgrading bus bracing in LVMCCs is discussed.<>