Voltage Ramp Starting - WEG SSW-07 Manual Del Usuario

Chapter 5 - prOGraMMING INFOrMatION aND SUGGeStIONS
5.1.1 Voltage Ramp
Starting
I/In
T/Tn
Current
Torque
Figure 5.2 - Characteristic curves of torque and current in a
1) Set the value of the initial voltage to a low value;
2) When a load is applied to the motor, set the initial voltage to a
value that makes the motor rotate smoothly from the instant it is
started.
3) Set the acceleration time with the necessary start time, initially
with short times, 10 to 15 seconds, and afterwards try to find the
best starting condition for the used load.
U(V)
Start
0
Enable
Figure 5.3 - Voltage ramp starting
NOTES!
 With long starting times, or when the motor is without a load,
vibration can occur during the start of the motor, therefore lower
the starting time;
 If faults occur during the start, check all the connections from the
Soft-Starter to the supply network, motor connections, supply
network voltage levels, fuses and circuit breakers.
current limitation start
100 %Un
Voltage Ramp
Tn
t(s)
Disable
37