Product Description:

The KL3403 is a three-phase power measurement terminal produced by Beckhoff and supplied in the KL Analog Input Modules series. It snaps onto a standard Bus Terminal rack, draws its operating power from the K-bus, and delivers true RMS data for three currents and three voltages to the controller. When installed in motor feeders or distribution branches, the module supports energy logging, phase-imbalance detection, and load-dependent control without requiring external transducers.

Each acquisition channel is digitized with 16-bit resolution, while a 21-bit internal word preserves calculation accuracy before scaling to the process image. Sampling occurs at 64,000 samples/s, and the terminal aggregates those samples and refreshes the fieldbus every 50 ms, so fast transients can be captured without excessive network traffic. The terminal maps its data into a 72-bit input and 72-bit output process image, supplying RMS values, power factors, and status flags while accepting parameter words. Voltage and current readings maintain a combined accuracy of 0.5% of full scale, and the enclosure carries an IP20 rating for finger-safe installation inside a cabinet.

The electrical interface is sized for feeder circuits. Current inputs are rated for 1 A through xA/1A current transformers and present only 33 mΩ of burden, which helps limit heating in the secondary loop, while phase voltages of up to 500 V AC can be connected through high-impedance 500 kΩ dividers. All six analog channels use the same true RMS measurement method, and the 64 kHz sampling rate allows the module to resolve distorted waveforms such as those produced by variable-frequency drives. With three current and three voltage inputs delivered to the controller in 50 ms cycles, the system can calculate active, reactive, and apparent power in real time and integrate those values for detailed energy monitoring.