Decentralised installation: Power supply in the field

This is an example of how this works in practice: a Murrelektronik customer designed a supply network for direct current drives of a feeding system. It was a comprehensive system with a central cabinet that did not use terminal boxes. The electrical engineers preferred a design with a decentralised power supply to save cabinet space, as they were familiar with a competitor's IP67 power supply. However, this unit couldn't handle the high inrush currents of the direct current drives.

By looking at Murrelektronik's Emparro67 they were able to make their design concept a reality. It is IP67 rated and can be installed close to the DC drives. Because the compact and rugged metal housing is fully potted the components are protected from mechanical stress as well as damage from dirt, humidity and cooling lubricants. Because the connections of the power supply are all on one side the unit could be easily installed directly under the machine. Voltage conversion (from 230V AC to 24V DC) now happens close to the load, keeping power loss low thereby lowering energy costs especially as compared with the centralised supply design.

Emparro67 also supplies the current required to start the high inductive loads of the DC drives. Its power boost function (supplying a nominal current of 150 per cent for up to 4s) without the risk of voltage drops is a key factor, while its integrated current limiting fuse provides additional protection. During standard operation, Emparro67 supplies a constant current of approximately 9A.

Manuel Senk, Murrelektronik product manager, is pleased with the success of this project. He says: "Our goal is a decentralised power supply, away from the central cabinet. Emparro67 is a key tool to help our customers to reach this goal. They can use smaller cabinets and the power supply is always next to the load where it is required."

Please visit www.murrelektronik.com for further information about the Emparro67 power supply.