The Schneider LV839237 is an MX opening voltage release designed for MasterPact MTZ drawout circuit breakers. It operates on a 277 V AC 50/60 Hz control circuit, drawing 4.5 W / 4.5 VA holding power, and triggers a trip when the control voltage drops to between 0.7 and 1.1 times the rated Un. Response time is 50 ms ±10% across the MTZ1, MTZ2, and MTZ3 frames.
The drawout mounting mode means this coil is not a panel-mount standalone device — it plugs into the breaker's drawout cradle as a field-installable accessory. If you are retrofitting an MTZ1, MTZ2, or MTZ3 frame, the 50 ms response time governs how quickly the breaker opens on a control-voltage loss; that timing is consistent across all three frame sizes. The 277 V AC control voltage is the line-to-neutral or line-to-line supply the coil expects — feeding it 240 V or 120 V will shift the trip threshold proportionally (0.7–1.1 Un). Holding power of 4.5 W / 4.5 VA is low enough that a standard control transformer or UPS can support it without derating.