The Bender VMD‑D‑ is a precision voltage and frequency monitoring relay designed for -phase ( N~AC) systems from  V to  V. It provides protection against over‑/undervoltage, over/under‑frequency, phase asymmetry, phase loss, and incorrect phase sequence. A user-friendly LC display, dual alarm relays, and configurable timing make it suitable for renewable energy inverters, UPS systems, and industrial control panels.

Key Features:

Model: VMD‑D‑ (LINETRAXX series)
Measurement Range: ‑phase voltage … V AC RMS; frequency …~ Hz ()
Supply Voltage: … V AC/DC
Protection Functions: Over/under‑voltage, over/under‑frequency, phase asymmetry, loss, sequence ()
Outputs: change‑over alarm relays ( A @  VAC)
Display & Controls: Multi‑line LC display, LEDs, menu navigation, password protection
Timing & Hysteresis: Adjustable start, response, and release delays with hysteresis setting
Housing: -module ( mm), DIN-rail mount, IP, optional transparent cover
Self-Test: Built-in automatic and manual self-test with error-code display

Bender – VMD423-D-2 – 3-Phase Voltage &amp; Frequency Monitoring Relay, 10–500 V AC

Bender – VMD423-D-2 – 3-Phase Voltage & Frequency Monitoring Relay, 10–500 V AC