news product and services
Variable speed drives for low power duties Emotron has developed a range of compact variable speed drives for low power applications. The VSA/VSC drives are equipped with several advanced functions for pumps, fans, compressors, mixers and cranes, the company says. The series is suitable for motors of 0.18-7.5 kW, and completes the Emotron range which now covers motor powers of 0.18-1,500 kW. The company says that the Emotron VSA/VSC drives offer efficient and protective starts and stops, minimizing mechanical stress and cycle times. The controlled stops eliminate the risk of water hammer and other damage, without the need for expensive motor-controlled valves, Emotron says. The drives also adapt motor speed to the level required, saving energy when compared to throttling valves or dampers. A built-in sleep function pauses the motor when it does not need to be run in order to keep up the required pressure.
WORLD PUMPS June 2007
Emotron VSA also has a builtin shaft power monitor which prevents damage and downtime. Over or underload situations can be immediately detected if a pump is running dry. Different load types can be handled by the drives, using for example constant torque for cranes and mixers and square
torque for pumps and fans, and they have eight programmable pre-set speeds. Emotron VSA/VSC can be supplied with a module for serial communication via RS232, RS485 and Modbus, or for communication via Profibus. A copy unit is available for easy transfer of settings between units.
The VSA/VSC drives for low power applications.
Shutoff valves are explosion proof A-T Controls has introduced a range of valves and valve assemblies for liquid and gas shutoff. The valves, which are approved to FM class 7400, 7420 and 7422, are a springreturn automated ball valve, explosion-proof limit switch and solenoid pilot valve, quarter-turn rack-and-pinion actuator design, superior valve seating, and patented stem seal system. The valves are configurable to a range of shut-off requirements and available in 3 piece or flanged models, 316SS or WCB trim, and ¼ in to 6 in sizes. The 3-piece valves offer choice of threaded, socket weld or butt weld end connections, while flanged valves are available in 150# or 300# flange rating. Assemblies are available with manual safety cocks or automated safety shut-off valves. Solenoids are approved for water-proof as well as explosion-proof environments.
www.worldpumps.com 13