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Efficient speed control for pumps and fans

Thursday 01. May 2008 - Beckhoff KL2791 Bus Terminal saves energy

The new KL2791 Bus Terminal enables direct connection of single-phase AC motors up to 100 W. In this way, the speed of capacitor, universal and shaded-pole motors can be reduced. This technique is particularly suitable for drives with quadratic load characteristic such as fans and pumps. The speed controller is extremely compact and is housed in a standard bus terminal with a width of 12 mm.
In many industrial nations, electric motors account for more than half of the electricity consumption so that they offer enormous energy saving potential. Speed control can easily reduce the excess energy requirement to the necessary degree. Beckhoff has expanded its
Bus Terminal I/O system for this application. The KL2791 Bus Terminal is suitable for use as a speed controller for single-phase AC motors up to 100 W. Besides the saving of energy, a decrease in speed also offers a reduction in noise and an increase in the service life of the motor.

The KL2791 Bus Terminal can be used in any bus system supported by the Beckhoff Bus Terminal system. The set value for the motor speed is specified by a 16-bit value. The motor is switched on and off with a practice-proven mains-synchronous pattern, so that the motor consumes less power and the speed falls significantly. This method is well suited to motors with fixed loads, such as pumps and fans, in order to achieve a setting range for the flow rate from 10 % to 100 %.