Product Description:

The EL3403-0000 is a three-phase power measurement terminal produced by Beckhoff within the EL EtherCAT Terminals series. Installed on a DIN rail alongside other I/O slices, it feeds real-time electrical data to a PLC over the EtherCAT fieldbus so that controllers can supervise load distribution, detect energy peaks, or support consumption-based maintenance in industrial automation cells. After evaluation, condensed status information is returned to the controller through an EtherCAT frame of 3 bytes.

The terminal uses a true RMS method to capture voltage and current waveforms, and its simultaneous sampling engine records each channel at 78,000 samples/s. This high rate works with six converters to digitize phase-to-phase and phase-to-neutral values in one cycle. Current is resolved down to 1 µA, while voltage steps are discerned at 0.1 mV, allowing fine tracking of small fluctuations on lightly loaded lines. Input data occupies 64 bytes in the process image, so harmonic values, active power, and apparent power are delivered each cycle without additional telegrams. Overall measurement uncertainty between 0 and 55 °C is held at 0.5% FS U/I; 1% P, which is suitable for energy balancing and load analysis tasks.

The circuitry withstands a line-to-bus dielectric stress of 1,500 V, and its measurement path accepts up to 500 V AC three-phase directly, or higher currents through an external x A / 1 A transformer that must not exceed the 1 A internal rating. A voltage input resistance of 500 kΩ minimizes loading of the monitored network, while the current input sees 220 Ω so that standard 1 A secondary transformers operate in their linear zone. All channels share a single-ended ground reference, which simplifies wiring. The simultaneous sampling design and 78 kHz update rate allow the EL3403 to analyze dynamic loads without aliasing or phase skew.