TOSHIBA- 5
TX Series 48 - 1250A
Other starting methods available in the TX Series are:
· Current Ramp: uses a closed current feedback PID loop to provide a linear
torque increase up to a Maximum Current level.
· Constant Current: current is immediately increased to the Current Limit point
and held there until the motor reaches full speed.
· Custom Curve: gives the user the ability to plot torque and time points on a
graph. The soft starter will then accelerate the motor following these points.
· Tachometer Feedback Ramp: uses a closed loop speed follower method
monitoring a tachometer input signal from the motor or load shaft. (PENDING)
Deceleration: the TX Series provides the user with the option of having the
load coast to a stop or controlling the deceleration by slowly reducing the voltage
to the motor upon initiating a stop command. The Decel feature is the oppo-
site of DC injection braking in that the motor will actually take longer to
come to a stop than if allowed to coast to a stop. The most common applica-
tion for the Decel feature is pumping applications where a controlled stop
prevents water hammer and mechanical damage to the system.
1.4 General Protection
Operation of the TX Series can be divided into 4 modes; Ready, Start, Run and
Stop. The CPU provides motor and load protection in all four modes. Additional
details on each protection feature can be found in later chapters.
Ready Mode: In this mode, control and line power are applied and the starter is
ready for a start command. Protection during this mode includes the monitor-
ing of current for leakage through multiple shorted SCRs. Other protection
features in effect are:
· Starter Temperature
· Shorted SCR
· Phase Reversal (if enabled)
· Line Frequency Trip Window
· External Input Faults
Note: The “Programming Mode” can only be entered from the Ready Mode.
During programming, all protection features and start command are disabled.
Start Mode: These additional protection functions are enabled when the soft
starter receives a valid Start command:
· Phase Reversal (if enabled)
· Start Curve
· Acceleration Timer
· Phase Imbalance
· Short Circuit / Load Pre-check (Toe-in-the-Water)
· Ground Fault
· External Input Faults
· Accumulated Starting FLA Units (I
2
t Protection)
· Overload Protection
· Thermal Capacity
Note: Shorted SCR and Shunt Trip protection are no longer in effect once the
soft starter goes into the Start Mode.
