Automation Direct Stellar SR55 Series, User Manual

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Appendix B: Soft Starter Application Considerations
Page B–15 Stellar
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SR55 Series Soft Starter User Manual – 1st Ed, Rev F – 09/18/2019
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Bre akaway Torque: The minimum torque required to achieve rotor movement for the motor
with its load.
Cur rent Limit: The current at which the ramp is held. For the SR55, current limit is only
active during start-up where it contributes to the motor control function. This feature
is particularly useful when starting high-inertia loads that require an extended start-up
period. (See also Overload Level.)
Dir ect-On-Line (DOL): The direct connection and disconnection of a motor from the AC main
supply by means of a contactor or switch. Acceleration and operation is at full mains
voltage only.
iER S: Intelligent Energy Recovery System. An advanced motor control technology proven
to reduce the energy consumed in fixed speed motor applications. It matches the power
consumption to the load required by intelligently monitoring and regulating energy
consumption, voltage, current, and power factor during the motor starting and running
stages. iERS automatically bypasses itself when it is not needed, and continues monitoring
to re-engage itself as needed.
Inr ush Current or Locked Rotor Current: The current that flows at the instant of connection of
a motor to the power source. It is limited by the impedance presented by a de-energized
motor and the applied voltage. Usually expressed as a multiple of motor full-load current.
Kic k-start Voltage: The percentage of supply voltage applied before commencing ramp-up
when a load has a high breakaway torque and the standard settings of pedestal voltage
may not allow sufficient torque to be developed by the motor to cause acceleration.
Loc ked Rotor Current: Same as Inrush Current (defined above).
Ove rload Level: The level of current at which the controller overload begins to integrate.
For the SR55, the overload detector is always active and provides protection against
prolonged over-current operation.
Ped estal Voltage: The voltage that the unit applies to the motor at start-up. It is expressed as
a percentage of the rated supply voltage.
Po w er Factor: The ratio, expressed as a trigonometric cosine, of the real power consumption
to the apparent power consumption.
Top of Ramp (TOR): The unit achieves Top of Ramp (TOR) when it completes the start-up stage
of motor control. (This occurs when the voltage applied to the motor first equals the main
supply voltage.)
Sof t -start: The regulation, by electronic means, of the supply voltage from an initial low value
to full voltage during the starting process. This over-comes the inherent drawbacks of a
switched supply. The motor torque is modified in proportion to the square of the voltage
applied.
Trip : A trip occurs when the unit removes power to the motor because its operation equals the
limit imposed by one of its self-protection features.