Description
The RM22UB34 is a modular single-phase voltage control relay from Schneider Electric’s Harmony range, designed to monitor voltage levels in industrial and building control panels. Operating in “window mode,” it detects both overvoltage and undervoltage conditions across a wide 80–300V AC/DC measurement range, making it a versatile protective device for equipment that needs to stay within a defined voltage band.
The relay features an adjustable hysteresis (5–50% of the threshold setting) and an adjustable time delay (0.1–30 seconds, ±10% of full scale) on crossing a threshold, helping avoid nuisance tripping from brief voltage transients. It measures true RMS voltage on a 250ms measurement cycle for accurate detection even with non-sinusoidal loads, and provides 2 changeover (DPDT) output contacts rated 8A for switching downstream equipment or alarms. With its slim 22.5mm width, it occupies the same DIN rail footprint as a standard 2-pole modular device, making it easy to fit into space-constrained panels. Used across a wide range of industrial automation applications — including hoisting, packaging, lifts, textile machinery, and water/pumping systems — the RM22UB34 is a reliable, general-purpose choice for protecting single-phase circuits and equipment from voltage excursions.