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Soft starters achieve up to 25 starts per hour
Carlo Gavazzi is introducing a new family of soft starters that feature a built-in bypass contactor with an external heat sink for enhanced performance. Applications include fans, blowers, pumps, conveyors, granulators, mixers and shredding machinery, lathes, carousels, cranes, industrial dryers and washing machines as well as car washes. Compared with existing devices on the market, the RSHR-MIDI starters are said to offer an increased number of starts per hour. Three-phase motors up to 400V/18A can make up to 50 starts per hour, and 250 starts/h are possible on 2.2kW motors. The overall range spans 1.5-22kW, comprising 6, 12 and 18A versions with 220, 400, 480 and 600V ac voltage models available. A 110-530V AC option provides global coverage for multiple voltages. The RSHR starters control two phases only, with the third phase continuously connected to the load. Soft starting and stopping are achieved by controlling the motor voltage using semiconductor devices. During normal running, these semiconductors are bypassed by internal electromechanical relays. Starting and stopping time as well as initial torque can be independently adjusted by built-in potentiometers with rotary controls. The result is vibration-free starting with a dramatic reduction in mains dips and lamp flicker. Din rail-mounted and only 45mm wide, the soft starters can be installed in the same space as existing models to provide up to 36 per cent higher rated outputs. The units also have built-in heat sinks, enabling them to be mounted side by side. Coloured lamps on the front panel indicate the power, ramping, bypass and overheat status. Options include over-temperature protection and end-of-ramp alarm output relays. The starters conform to the requirements of IEN 60947-4-2 and EMC Directive 89/336/EEC. They carry CE marking, UL and cUL approvals and can be CSA approved if required. Top Stories from Scientist Live: The truth about organic farming | | Planting the nano-bulls-eye on cancer | | Racial variations in the human genome | | Mental Training Affects Distribution of Limited Brain Resources | | Understanding nitrogen fixation in algae | | Historically, climate change spurs wars | | Bioelectronics breakthrough | | |
