Specifications include, but are not limited to:The City of Statesville is seeking qualifications from qualified professionals for the general substation testing, specialized maintenance, and minor modifications. All firms submitting proposals must have demonstrated experience and expertise in the work required. This experience should include (test listings are minimum requirements and are not all-inclusive): Substation power transformer maintenance with units up to 100 kV, 20 MVA OA rating. o Tests should include: Overall Transformer Power Factor and Capacitance Bushing Power Factor and Capacitance Transformer Turns Ratio DC Winding Resistance Excitation Current Oil Quality Review Dissolved Gas Analysis Collection and Review Leakage Reactance Sweep Frequency Response Analysis Partial Discharge Visual Inspections o Provider should be able to: Replace Transformer Bushings Replace and diagnose fan and fan control problems Replace cooling fins Perform oil dehydration and filtering as necessary Re-gasket radiators and/or bushings Distribution regulators (23 kV) o Ratio tests on all windings and tap connections o Operational tests using rated voltage o Polarity Tests o Resistance Measurements of windings excluding control and tap changer voltage supplies o Insulation Power Factor Test o Insulation Resistance Test o No-load losses o Load losses and impedance at rated current and frequency o Applied potential test
