Eaton S611, User Manual

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18 S611 Soft Starter
MN03902011E—May 2012 www.eaton.com
Starting/Stopping Options
The following starting options are available in the S611 soft starter:
Voltage Ramp Start
This is the most commonly used mode of soft starting. Starting at an initial value set by the
Initial Torque parameter, the voltage applied to the motor is gradually increased at a rate that
will reach rated voltage at the end of the ramp time, set by the Soft Start Time parameter. As
the voltage increases the motor develops torque that accelerates the load toward full speed.
When the S611 senses that the motor has achieved synchronous speed, it quickly completes
the voltage ramp and closes the bypass contactor. (See figure below.)
It should be noted that a lightly loaded motor takes less torque, and thus lower voltage and
time to accelerate to full speed. For this case the S611 will go into bypass before the ramp
reaches full voltage. In other words, the S611 will go into bypass before the
Soft Start Time
has elapsed.
Ramp Start
Kick Start —The Kick Start feature works in both the Voltage Ramp Start and Current Limit
Start modes. By momentarily applying up to a two (2) second pulse of current to the motor, it
provides an initial boost in torque to overcome the static friction common in some applications.
The level of torque boost is set by the
Kick Start Torq parameter and the duration of the “kick”
is set by the Kick Start Time . Setting the Kick Start Time to 0 disables this feature.
Initial
Torque
Kick
Start
Torq
Kick Start Time
100%
Bypass Bypass
Voltage
Ramp
Rated
Voltage
Soft Start Time
tr
Start Run
T
o
rque
Time (Seconds)
100%
Start Run
Speed
Time (Seconds)
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