BECKHOFF DK9222-1009-0006 - Manual (Page 4)

I/O
Bus Terminal
Application Note DK9222-1009-0006
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Optimisation – speed control using the KL2791
In neither case the power consumption of the pump is affected; therefore, the use of the single-phase AC motor terminal makes
sense in order to achieve a reduction in the consumed power.
5 4 2 1 3
KL2791
Volume rate of flow
Pump
Start-up
phase
1 st cut Constant
cut
Exit Move-out
phase
Tool drive active
Cooling lubricant consumption
Energy consumption
Fig. 4 Optimised control with the KL2791
Using the KL2791 single-phase AC motor terminal, a single-phase AC motor with a maximum power consumption of 0.1 kW
can be operated with speed control depending on the process data. L1 and N of the motor are wired directly to the terminal;
this is in turn integrated in the control environment via a Bus Coupler or connected directly to an embedded device.
The controller specifies the set value for the motor speed in the form of a 16-bit word; the speed is regulated internally in the
terminal: 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 control range for the flow rate from 10 % to 100 %.
– 1-channel AC motor speed controller, 230 V AC, 100 VA www.beckhoff.com/KL2791
– The modular fieldbus system for automation www.beckhoff.com/Busterminal
New Automation Technology Beckhoff 4