The Schneider Electric LV839264 is an MN-type undervoltage release for MasterPact MTZ drawout circuit breakers. The release operates on a 380/480 V AC/DC control circuit at 50/60 Hz. It draws 4.5 W / 4.5 VA holding power. The tripping thresholds are 0.35 to 0.7 Un on opening and 0.85 Un on closing.
This is a drawout-mounted accessory — it plugs into the MasterPact MTZ cradle, not the fixed front panel. That means the release travels with the breaker cassette during racking, so the undervoltage protection is always present regardless of whether the breaker is in the connected or disconnected position. The response time is 40 ms ±5% for MTZ1 frames, and 90 ms ±5% for MTZ2 and MTZ3 frames.