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SPX advanced – description of parameters
SPX ADVANCED APPLICATION MANUAL
SVCH0203—October 2017 www.eaton.com
5.7.2.1 Reduced flux function
Reduced flux function is used to decrease the
magnetization current below a certain frequency limit. This
function is used in systems where high starting torque is
not needed. This function CAN NOT be used in any situation
where motor nominal torque from zero speed is required.
Code
ID
Parameter
Notes
P1.7.2.6
627
Reduced Flux frequency
A frequency point where flux starts to reduce to a level defined by Reduced Flux Level
toward the zero speed.
P1.7.2.7
Reduced flux level
This parameter defines the flux level when the output frequency is zero. The flux is
reduced linearly from ID1614 to zero frequency.
Output frequency
Motor
Magnetizerion
Red.
Flux Hz
Red. Flux
5.8 Motor control
Open Loop control
Open loop control controls the motor without encoder
feedback from the motor shaft. Control mode selections 0,
1 and 2 are open loop control modes.
Slip
Induction motor torque is based on slip. When load
increases also slip will increase. Slip is the speed that rotor
is behind of stator electrical frequency.
Right hand side picture presents torque that is produced by
induction motor when connected directly on line.
1. Motor Synchronous speed. Motor is taking only
magnetization current
2. Motor nominal operation point. Motor is producing 100
% of rated torque and power. Actual shaft speed is
motor nominal speed and motor takes nominal current
3. Pullout torque. This is point where motor produced
torque start to decrease when slip increases. After this
point motor will stop if load is not reduced
~600 %
Torque
100 %
100 %
3
2 1