The partially controlled RSGD series and the fully controlled RSGT series enable the soft start of three-phase asynchronous motors from 5.5 kW to 75 kW at 400 VAC without complicated settings. Three independently adjustable potentiometers for soft start time, soft stop time and maximum full load current (FLC) allow the user to adapt the devices to the relevant applications.

A self-learning algorithm optimizes the motor's start-up and run-down parameters at each start in accordance with these user-specified parameters. Class 10 motor overload protection and other integrated monitoring functions such as the detection of phase sequence and phase asymmetry faults and the monitoring of undervoltage and overvoltage eliminate the need for additional monitoring components in the electrical switchgear.

The robust design allows up to twelve motor starts per hour. A mini-USB connector on the front or, as an option, a fixed RS485 Modbus RTU interface enables easy parameter setting and real-time monitoring via software. In addition, the data logged by the device for the last 32 starts can be queried. The software is available as freeware. The versions with the wide voltage range up to 400 VAC do not require an additional power supply.

Since July 2021, three-phase asynchronous motors from 0.75 kW to 1,000 kW must have an efficiency rating of IE3 or higher in accordance with EU ecodesign regulations. However, the starting currents of these high-efficiency motors are many times higher than those of previous standard motors. Soft starters prevent possible faults in the mains supply caused by the high starting currents, they extend the service life of the motors and reduce wear and tear on the systems caused by mechanical stresses such as vibrations.

The devices in the RSGD and RSGT series are suitable for controlling 3-phase asynchronous motors with constant speed, where the starting current or the load on the motor must be reduced during starting and stopping processes. Typical applications include compressors, pumps, fans and conveyor belts in industrial automation and in heating, ventilation and air conditioning technology.

With communication function

The soft starter housings are compact in design, measuring 45 mm or 75 mm for the RSGD series (partially controlled) and 45 mm, 75 mm or 120 mm for the RSGT series (fully controlled), depending on the type. A QR code on the front of the devices links to a help menu for troubleshooting. Under the flap behind it is an RS485 Modbus RTU interface in the form of a mini USB connector, which can be used to connect the soft starter to a laptop.

The configuration software SCS (Softstarter Configuration Software), which is available free of charge, enables the setting, control and monitoring of up to 247 motor soft starters. The operating personnel can configure the soft starters individually and transfer configuration files bidirectionally, monitor the current values and read errors and alarms as well as the data from the last 32 starts.