The Schneider LA1LC072N is an instantaneous undervoltage trip (undervoltage release) from the TeSys Integral range, designed to drop out a contactor or motor starter when the control voltage falls below a set threshold. It operates on a 415-440 V AC control circuit at 50/60 Hz, with a tripping threshold of 0.35 to 0.7 times the rated control voltage (Uc). This is a service part — packaged as a set of 10 — intended for replacement or repair of existing TeSys Integral assemblies. It has no time delay, meaning the trip acts immediately when voltage drops below the threshold.
Sourcing Reality — Obsolete, No Direct Successor
The LA1LC072N is marked obsolete by the manufacturer.
If your panel runs a 400 V control transformer, this part sits within the 0.8 to 1.1 Uc operating limits, but the tripping threshold (0.35-0.7 Uc) means it will release the contactor when voltage drops to roughly 145-308 V AC. That range is typical for undervoltage protection on 400 V class systems. Inrush power draw is 8 VA AC; holding power is 4 VA AC. These numbers matter for transformer sizing in the control circuit — the inrush surge is brief but must be within the transformer's capability.