Only limited replacement parts still available for sale.
The SMC-2™ Controller is a compact, multi-functional, versatile solid-state controller used in starting standard three-phase squirrel-cage induction motors. Three standard modes of operation are available within a single controller:
- Soft Start
- Current Limit Start
- Full Voltage Start
- Optional Soft Stop (Requires Interface Module)
The SMC-2 Controller is available in eight sizes: 5, 9, 16, 24, 35, 54, 68, and 97 A. It is offered in three voltage ranges: 200…230V, 380…460V, and 500…575V, 50/60 Hz. It can be used in two configurations: as a series controller and as a motor controller with an interface option.
The SMC-2 Controller is designed to operate in series with an electromechanical motor starter. The series mode has the following features:
- Eliminates the need for additional control wiring, simplifying initial installation.
- Works in unison with an existing electromechanical motor starter for easy retrofits.
- Allows easy set-up with digital adjustments eliminating the guesswork of setting analog potentiometers.
The SMC-2 Controller with the interface option is designed so it can be operated without an electromechanical motor starter. The SMC-2 Controller with the interface option offers the following features:
- Provides ON/OFF control directly to the controller through an external pilot device. In many applications the interface option may eliminate the need for an additional contactor if electrical isolation or soft stop is not required. This reduces panel space requirements.
- Provides a selectable auxiliary contact, which operates as either an instantaneous or up-to-speed contact, making it available for a wide variety of control schemes.
- Provides a Soft Stop feature that extends stopping time to minimize load shifting or spillage during stopping.
This built-in feature of the SMC-2 Controller is used to save energy on applications where the motor is lightly loaded or unloaded for long periods of time.
In applications where the SMC-2 Controller is exposed to high or abnormal line transients, an optional protective module is available and can be mounted on both the line and load side of the unit. The protective module contains MOVs (Metal Oxide Varistors) that protect the SCR from line surges and snubber networks to shunt noise energy away.
Modes of Operation
- Soft Start — This method has the most general application. The motor is raised from an initial torque value to full voltage. This initial torque is adjustable between 0…70% of locked rotor torque. The motor voltage is gradually increased during the acceleration ramp time, which can be adjusted from 2…30 seconds.
- Current Limit Starting — This starting mode is used when it is necessary to limit the maximum starting current. It can be adjusted for 25…550% of full load amps. If the motor is not up to speed after the selected time elapses, the controller will transition to full voltage.
- Full Voltage Starting — This mode is used for applications requiring across-the-line starting. The ramp time is set for less than 1/10 second as shown.
- Soft Stop — The Soft Stop feature is available with an optional interface module. This function can be used with applications that require an extended coast to rest. The voltage ramp down time can be set from 5…110 seconds. The motor will stop when the motor voltage drops to a point where the load torque is greater than the motor torque.