The LA1LC070Q is an undervoltage trip (undervoltage release) from the Schneider TeSys Integral range, designed to drop out a contactor or starter when the control voltage falls below a set threshold. It triggers at 0.35 to 0.7 times the rated control voltage (Uc), which for this variant is 380/400 V AC at 50/60 Hz. The built-in 0.2 s time delay prevents nuisance tripping during brief sags or switching transients.
The 380/400 V AC control voltage is the nominal coil rating — the part operates reliably between 0.8 and 1.1 times Uc (304 to 440 V AC). The undervoltage threshold of 0.35 to 0.7 Uc means the trip activates when the line drops to roughly 133 to 280 V AC, depending on the adjustment setting. That 0.2 s delay is enough to ride through a momentary dip from a large motor start but short enough to drop the load before a prolonged brownout damages the contactor's coil. Inrush power is 8 VA AC; holding power drops to 4 VA AC once the armature seals, so the control transformer only needs to handle the inrush transient, not a continuous high draw.
Deployment context
This undervoltage release clips onto the front of a TeSys D or F contactor, occupying the same slot as a standard coil or auxiliary contact block. It does not add depth beyond the contactor's own envelope, so it fits existing panel layouts without re-spacing the DIN rail. The 0.2 s delay is factory-set and not field-adjustable — if the application needs a longer ride-through, a separate time-delay relay upstream is the usual workaround.