WEG SSW-06.0205 User Manual page 134

Controle
de Torque
P400
P102
P401
P120 =2
P402
P121
P404
P122
P405

P104 0
P406
P125 =3
P640
P126
P127
P128
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CHAPTER 7 - APPLICATIONS AND PROGRAMMING
Stopping (P1240 and P125=3):
1) Quadratic deceleration torque, 3 points=quadratic;
2) Applied to high water columns with high pressures;
3) This control is used when it is difficult to achieve a gradual pressure
drop without sudden pressure oscillations, mainly at the start of the
stopping process;
4) The best way to perform this is to use the load curve as a base and
set the 3 points 10% to 15% lower;
5) Set P128 initially to 50%;
6) Set P127 so that at the beginning of the stopping process, the
pressure decreases gradually and no sudden pressure oscillation
occurs;
7) Set P126 so that at the end of the pump stopping process the motor
is not still enabled.
Tn(%)
Start
P121
0
P102
Maximum Time
Enable
Figure 7.21 – Hydraulic pump stopping with quadratic torque, 3 points
8) If the load shows a higher initial torque, then use the quadratic torque
control (P120=3 points).
Figure 7.22 – Manometer showing the pressure drop, torque control
NOTES!
1) The main purpose of the torque control types applied to the stopping
process is to maintain the drop in the pressure ramp as linear as
possible, decreasing the pressure gradually and thus preventing
sudden pressure oscillation, at the beginning, middle and at the end
of the stopping process;
2) As already described in the pump control, the use of a measuring
instrument is required to measure the pressure and obtain the best
setting;
3) Remember: constant torque control is suitable for the greatest number
of applications and its use is very easy.
Speed
P122
Tn Nominal
Load Torque
P127
P128
P104
Torque Control
Disable
%Tn
Speed
Tn Nominal
P127
0
P128
P104
Disable
P126
t(s)
P126
t(s)
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