Overview

Portfolio of the SIRIUS 3RK43 MCU motor starter family

The SIRIUS MCU motor starter family (MCU = Motor Control Unit) rounds off the bottom end of the SIRIUS motor starter range.

A system solution for the control of AC loads outside the control cabinet for operation in the field represents the application area for this motor starter series in a high degree of protection.

The MCU product range extends from I/O-controlled motor starters – addressing a central sub-distribution board via I/O stations – in a plastic enclosure for simple applications to motor starters with AS-i communication for demanding tasks.

The MCU motor starters are completely pre-wired inside, have a high degree of protection and are designed for switching and protecting any AC loads. They are mostly used on standard three-phase motors in direct or reversing duty up to 5.5 kW at 400/500 V AC (electromechanical switching).

The motor and short-circuit protection integrated in the MCUs consists of an electromechanical controlgear assembly and a motor starter protector unit for short-circuit protection.

SIRIUS MCU motor starters have the following main features:

• Direct-on-line or reversing starters
• Up to 5.5 kW
• Plastic enclosures
• Electromechanical switching
• Integrated lockable repair switch
• Short-circuit protection with SIRIUS 3RV motor starter protector
• Overload protection with thermal release (bimetal)
• Power and load connection by means of an M screw
• Main power loop possible (daisy chain; max. 2 x 6 mm²)
• Robust and widely used M12 connection method for the AS-i bus connection
• The LEDs (with a AS-i bus connection) can provide comprehensive diagnostics of the device on the spot.

MCU motor starters controlled On-site in a plastic enclosure

This motor starter is designed for the autarkic operation of any AC load – preferably induction motors.

Locally controlled MCU motor starters in a plastic enclosure

Just the infeed needs to be connected, and no bus or other connection to a coordinating control.

The motor is protected against short-circuits (50 kA ) and overloads (thermal overload releases) by an integrated circuit breaker. No further measures are required for this function either (such as back-up fuses).

This motor starter is equipped with a "MAN-0-AUTO" key-operated switch for selecting manual, 0 or automatic operating modes, which prevents unauthorized switchover.

In automatic mode the motor can be controlled automatically over the sensors connected (level switch, temperature or pressure switch). The reversing starter is even equipped with a connection option for 2 sensors, making direction reversal dependent on the sensors possible. On the reversing starter the controls with interlock are pre-wired.

In manual operating mode, powering up/down or switching the direction of rotation is performed manually by the operator with a knob-operated control switch.

I/O-controlled MCU motor starters in a plastic enclosure

These motor starters offer an economical solution for controlling induction motors distributed in the field.

I/O controlled MCU motor starter in a plastic enclosure

The internal controls (contactors) are operated by external control with 24 V DC.

On the reversing starter, the controls with interlock are pre-wired.

The status of the circuit breaker can be queried through its floating changeover contact. The status can adopt the following positions: activated - the contact is closed - and deactivated or tripped - the contact is open (I/O control).

MCU motor starters with AS-i bus connection in a plastic enclosure

This motor starter version offers an economical solution for controlling and monitoring conveyor belts, pumps, fans or compressors.

MCU motor starter in a plastic enclosure, AS-i communication

On this MCU the control commands and the status queries are sent over the AS-i bus. The yellow cable (bus) and the black AS-i cable for 24 V DC AUX are connected through the M12 plug.

The transparent enclosure part permits monitoring of the status LEDs. These MCUs come completely pre-wired inside.