TOSHIBA - 6
TX Series 48 - 1250A
Run Mode: The soft starter enters the Run Mode when it reaches full output
voltage
and the motor current drops below the FLA setting (motor nameplate
FLA plus service factor) for a predetermined period of time. During the Run
Mode these additional protection features are enabled:
· Running Overload Curve
· Phase Loss
· Under Current / Load Loss
· Over Current / Electronic Shear Pin
· External Input Faults
Stop Mode: Once a Stop command has been given, the TX Series protec-
tion features change depending on which Stop Mode is selected.
· Decel Mode: retains all protection features of the Run Mode. At the end of
Decel, the motor will be stopped and the protection features change as
indicated below.
· Coast-To-Stop Mode: power is immediately removed from the motor and the
soft starter returns to the Ready Mode. Additional protection features activated
when the stop command is given include:
· Coast-Down / Back Spin Timer
· Starts-per-Hour
· Time Between Starts
· External Input Faults
1.5 Thermal Overload Protection
The TX Series plays an important role in the protection of your motor in that it
monitors the motor for excessive thermal conditions due to starting, running or even
ambient conditions. The TX Series has a Dynamic Thermal Register system in
the CPU that provides a mathematical representation of the thermal state of the
motor. This thermal state information is kept in memory and is monitored for
excesses in both value and rate of change. Input is derived from current
imbalances and (optional) RTD measurements making it dynamic to all processes
involving the motor. The TX Series monitors these conditions separately during
Start and Run modes to provide proper thermal overload protection at all times.
Start Mode overload protection is selectable using one of three methods:
· Basic Protection: I
2
t data is accumulated and plotted based on an Overload
Curve selected in programming. This is programmed per NEMA Class 5-30
standard curves and is based on the Locked Rotor Current (from the motor
nameplate) as programmed into the soft starter.
· Measured Start Capacity: the user enters a measured amount of thermal
capacity from a pre-selected successful start as a setpoint to the Thermal
Register for the soft starter to follow.
· Learned Curve Protection: the user sets the soft starter to the “LEARN” mode
and starts the motor under normal starting conditions. The CPU then
samples and records 100 data points during the start curve, analyzes them
and creates a graphical representation in memory. The soft starter is then
switched to Curve Follow protection mode and monitors motor performance
against this curve. This feature is especially useful in initial commissioning
tests to record a base line performance sample (in this case, it is not
necessarily used for motor protection).
