AT/ATR 3 & 4 Series Current Transducers combine a current transformer and a signal conditioner into a single package for applications from 200A to 2000A. The AT version is Average Responding for use on linear (sinusoidal) loads. The ATR version is True RMS for use on distorted waveforms found in VFD or SCR ouputs. Available in a solid-core case.

Designed to provide an analog current reading for monitoring, data logging and panel meter applications, these transducers offer a choice of 0–5VDC, 0–10VDC or 4–20mA average responding or True RMS outputs. Self-powered and split-core options make these a cost-effective choice as a PLC input in motor status applications or where VFDs are involved

Selecting the right transducer: The current waveform of a typical linear load is a pure sine wave. AT transducers measure the peaks of these sine waves, then calculate the average amperage. This works well on constant speed linear loads in “clean” power environments. Select AT transducers for strictly linear loads on “clean” power.

VFD and SCR output waveforms are rough approximations of a sine wave. There are numerous spikes and dips in a mathematical algorithm called “True RMS,” which integrates the actual waveform over time. The output is the amperage component of the true power (heating value) of the AC current waveform. True RMS is the only way to accurately measure distorted AC waveforms. Select ATR transducers for nonlinear loads on “noisy power.”