6 Parameters6.5 Parameter descriptionDE1 variable speed starter 09/14 MN040011EN www.eaton.com 95V/f Control modeVolts per Hertz control (V/Hz characteristic) refers to the DE1 variable speedstarter control method in which motor voltage is regulated so that it ismaintained at a specific ratio relative to frequency. If the voltage-to-frequency relationship is constant, this is referred to as a "linear V/Hzcharacteristic curve."In a standard application, the characteristic values (①) in the V/Hzcharacteristic curve (e.g., 400 V/50 Hz) will match the connected motor'srated operational data (refer to the motor's rating plate):• Output voltage = Rated operating motor voltage (P-07)• Cut-off frequency = motor rated frequency (P-09)figure 66: V/f-characteristic curveVoltage increase (Boost)Below approx. 50% of the motor's rated operational data, the correspondingefficiency (η) and power factor (cos ϕ) will drop sharply. The runoutcharacteristics will worsen and the current consumption will increase, withthe severity of these changes depending on the type of rotor and itscharacteristics.Using the voltage boost function (boost, P-11) can mitigate these effects onthe starting torque and on the motor's runout characteristics at lowfrequencies.The voltage boost (P-11) can be set to values of up to 40% of the motor'srated operating voltage (P-07). The voltage boost configured with P-11 will beeffective up to approx. 50% of the rated motor frequency (P-09).￫ The higher start voltage (boost) will result in a higher motorcurrent and, accordingly, in increased motor heating. Increasedmotor cooling (external fans) may be required.[%]Uf [Hz]P-07P-02 = 0 Hz P-09 P-01U[%]f [Hz]P-110...40 % P-07P-07P-0950 % P-09 P-01① ①P-02 = 0 Hz
