The LV839234 is an MX-type opening voltage release from Schneider Electric, designed for MasterPact MTZ drawout circuit breakers. It operates on a 48 V AC supply at 50/60 Hz or a 48–60 V DC control circuit, drawing 4.5 VA / 4.5 W holding power. The tripping threshold spans 0.7 to 1.1 times the nominal control voltage (Un), and the response time is 50 ms ± 10 % across the MTZ1, MTZ2, and MTZ3 frames.
The 48 V AC / 48–60 V DC control voltage range matches standard control transformers and DC power supplies found in MV switchgear panels. The 0.7–1.1 Un tripping threshold means the coil will release the breaker if the control voltage drops below 33.6 V AC or rises above 52.8 V AC — a useful brownout detection feature. The 50 ms response time (±10 %) is consistent across all MTZ frame sizes, so the same coil can be used on MTZ1, MTZ2, or MTZ3 drawout cassettes without retiming the protection scheme.
Integration Note
Mounting mode is drawout — the coil plugs into the MTZ cassette's control wiring harness, not onto a DIN rail. The 4.5 VA / 4.5 W holding power is low enough that a standard 48 V DC power supply can drive multiple coils in a lineup without excessive derating. Verify the free-wheel diode polarity on the DC control circuit before energizing; the MX coil does not include internal suppression.