The Schneider Electric G12UVR230AC is an MN undervoltage release for the GoPact MCCB 125 range, operating on a 240 V AC 50/60 Hz control circuit.
The threshold tripping voltage is 0.35 to 0.7 Un for opening and 0.85 to 1.1 Un for closing. That means on a 240 VAC control circuit, the release will drop the breaker when the voltage falls between about 84 V and 168 V, and it will reset (allow closing) when the voltage is back between about 204 V and 264 V. This hysteresis prevents nuisance chatter near the dropout point. Response time is listed at 25 ms — fast enough for most motor and feeder protection schemes where undervoltage tripping is required, but not a high-speed transfer application. The pick-up power consumption peaks at 5 VA, holding at 3.5 VA, so the control transformer sizing is modest.