Altistart 01 Soft Starters Page 11 Introduction

11 Altistart 01 & U01 soft starters for asynchronous motors Introduction ATS01N2 & ATSU01N2 soft starters Functions (continued) Initial (or starting voltage) The initial voltage applied to the motor (the level at which the voltage ramp begins) can be adjusted by a potentiometer on the face of the Altistart 01 soft starter. The initial voltage level can be adjusted from approximately 30 to 80% of the AC line voltage. Since the resultant motor torque varies in proportion to the square of the applied voltage (see the Torque Characteristics diagram), the scale on the front of the ATS01 is calibrated from A to E rather than from 30 to 80%, with A being the lowest level and E being the highest level. A lower setting will reduce motor current and torque during starting. Set this level to the minimum required that will result in motor rotation immediately after a start command. If no level of adjustment here starts immediate motor rotation, use the Boost function. Refer to diagram on page 10 for more detail. Boost (kickstart function) If the Boost control input is active (connected to LI+ or +24 V) when a start command is given, full line voltage will be applied to the motor for the first 200 mS of soft start operation. Thereafter, the normal voltage ramp will resume. Use this function to start high inertia loads or applications with a high level of starting friction. Refer to diagram on page 10 for more detail. Motor up to speed The ATS01 soft start provides a logic signal to indicate that the starting voltage ramp is complete and the motor is up to speed. This signal is provided by an open collector output illustrated in the diagrams below. An external power supply is required to complete this circuit. Fault/stop The ATS01 soft start provides a relay contact to indicate either that it has detected a fault or that it has stopped running the motor. The normally-open contact between terminals R1A and R1C closes when a run command is provided at LI2. The relay contact opens under either one of the following two conditions: The contact opens instantly when the soft start detects a fault condition. The contact opens when the motor voltage reaches zero after a stop command. This information can be used to sequence a contactor if both line isolation and soft stop are needed in the same application. Pull Up Resistor External Power Supply (6 to 30 Vdc) External Power Supply (6 to 30 Vdc) Max Current 200 mA LO1 ATS01 Signal 6 to 30 Vdc = motor stopped 0 Vdc = motor up to speed 6 to 30 Vdc = motor up to speed 0 Vdc = motor stopped External Power Supply Common Max Current 200 mA ATS01 External Power Supply Common OR COM LO1 COM 0 0 0,25 0,5 0,75 1 N/Ns U 0,85 U 0,6 U T Tr 3 Tn 2 Tn Tn Torque Characteristics This diagram shows the torque/speed characteristic of a squirrel cage motor in relation to the applied voltage. The torque varies in proportion to the squared ratio of the applied voltage to the motor's rated voltage at a fixed frequency. For example, 1/2 voltage results in approximately 1/4 torque. The gradual increase in the voltage helps prevent the instantaneous current peak on startup. 6 to 30 Vdc = motor stopped 0 Vdc = motor up to speed 6 to 30 Vdc = motor up to speed 0 Vdc = motor stopped

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