Rockwell Automation 150 MNL/SMC DIALOG+/APP-PROD GUIDE - Manual (Page 10)

1-2 STC Starting Torque Controller
Modes of Operation Across-the-Line Response
Excessive motor starting torque can damage the motor and driv
equipment. Figure 1.2 illustrates the torque developed in a typical
across-the-line start.
Figure 1.2 Torque Developed in a Typical Across-the-Line Start
STC Controller Response
The STC controller reduces the magnitude of starting torque surges as
illustrated in Figure 1.3. This limits the starting shock to the motor
and drive
train.
Figure 1.3 STC Controller Respons
Across-the-Line Response Versus STC Controller Response
Figure 1.4 compares a typical across-the-line start response and the
STC controller response.
Figure 1.4 Across-the-Line Response Versus STC Controller Response
10
75
50
25
0
-25
-50
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Time (sec.)
Torque
NM
10
75
50
25
0
-25
-50
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Time (sec.)
Torqu
NM
100
75
50
25
0
-25
-50
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Time (sec.)
Torque
NM