PA7300 Instruction Manual - TECO-Westinghouse Motor Company

(33) Energy-saving tuning operation (Cn-49 to Cn-52)In the energy-saving mode (Sn-09 = X1XX) the optimum voltage is calculatedaccording to load power and the voltage is supplied to the load. However, since thesetting motor constants are different depending on temperature variation or use ofother manufactures’-motors, the optimum voltage is not always output. At tuningoperation, operation is controlled so that the optimum operating status can beobtained by fine adjustment of voltage.(a) Tuning Operation voltage Limit (Cn-49)Limits the range where voltage is controlled by tuning operation. Setting is madein the units of % of rated voltage. By setting this value to 0, tuning operation isnot performed.Cn-49-Cn-49V HOLD(b) Tuning Operation Control Cycle (Cn-50)Sets the control cycle of tuning operation.(c) Tuning Operation voltage Step (Cn-51, 52)Sets voltage variation width of one tuning operation cycle. Setting is made in theunits of % of rated voltage. By increasing this value, rotation speed variationbecomes larger. This voltage variation width is set at tuning stanting voltage100% and 5%. With the other voltage value, voltage variation width obtained bylinear interpolation is set.VoltageVariationWidthCn-51Cn-525%100%Output Voltage(34) Energy-saving coefficient K2 (Cn-58)Voltage at which the motor efficient will be the maximum is calculated by using thiscoefficient at operation in the energy-saving mode, and the calculated value is to bevoltage reference. This value is already set to the value of a TECO motor as theinitial value. By increasing the energy-saving coefficient, output voltage becomeslarger.61