DEIF RMV-112D High-Precision Voltage Protection Relay Detailed Information

The DEIF RMV-112D is a compact,multifunctional voltage protection and monitoring relay from DEIF A/S,engineered specifically for generator set protection,mains failure detection,and safe synchronization in power generation and industrial backup systems.As a dedicated under/overvoltage and vector shift relay,it ensures rapid disconnection of generators during grid faults—protecting equipment and maintaining stability in islanded or parallel-to-grid operations.

Housed in a 45 mm DIN-rail module with intuitive LED indicators and configurable logic outputs,the RMV-112D delivers utility-grade protection performance in a cost-effective package,widely trusted in marine,oil&gas,data centers,and microgrid applications where voltage integrity is non-negotiable.

Application Scenarios

During commissioning of a 10 MW solar-plus-storage microgrid in the Caribbean,engineers faced repeated tripping of diesel backup generators during cloud-induced PV ramp events.The legacy relays misinterpreted rapid voltage dips as grid collapse,causing unnecessary islanding.After replacing them with the DEIF RMV-112D,the team leveraged its programmable vector shift detection and adaptive voltage window timing to distinguish between transient dips and true grid loss.The result?Seamless ride-through during solar fluctuations and zero false trips over 18 months of operation.For this project,the RMV-112D became the silent guardian that kept the hybrid system stable—proving that precision timing matters as much as protection thresholds.

Parameter

Main Parameters Value/Description

Product Model RMV-112D

Manufacturer DEIF A/S(Denmark)

Product Category Voltage Protection Relay/Mains Failure Relay

Input Voltage Range 50–690 V AC(phase-to-phase or phase-to-neutral),50/60 Hz

Measurement Accuracy±0.5%of reading

Protection Functions 27(Undervoltage),59(Overvoltage),78V(Vector Shift),81O/U(Optional via firmware)

Trip Response Time Adjustable:10 ms–10 s(per function)

Outputs 2 programmable SPDT relays(8 A 250 VAC)

Vector Shift Detection 2°–30°adjustable,with inhibit during transients

Power Supply 24–230 V AC/DC(universal)

Communication(Optional)None(basic model);upgradeable to RMV-212D for Modbus RTU

Operating Temperature-25°C to+70°C

Standards Compliance IEC 60255,EN 61000-6-2/4(EMC),IEEE C37.90

Technical Principles and Innovative Values

Innovation Point 1:True Vector Shift Discrimination–Unlike basic undervoltage relays,the RMV-112D continuously monitors the angular displacement between pre-fault and post-fault voltage vectors.This allows it to detect actual grid separation(e.g.,due to upstream breaker opening)while ignoring symmetrical sags—critical for avoiding nuisance trips in weak grids.

Innovation Point 2:Dual-Threshold Timing Logic–Each protection function(27/59)supports independent start and trip delays,enabling compliance with G59/28,VDE-AR-N 4110,and other grid codes requiring staged responses to voltage anomalies.

Innovation Point 3:Immunity to Harmonic Distortion–Built-in anti-aliasing filters and RMS calculation ensure accurate voltage measurement even with THD>15%,common in inverter-based resources or industrial loads.

Innovation Point 4:Field-Configurable Without Software–All settings(voltage levels,delays,vector angle)are adjusted via front-panel potentiometers and DIP switches—ideal for remote sites without laptops or configuration tools.

Application Cases and Industry Value

On an offshore drilling rig in the Gulf of Mexico,the DEIF RMV-112D was deployed to protect three 2.5 MW generator sets operating in parallel with a shore-power connection.During a lightning strike that caused a 300 ms voltage dip on the mainland grid,older relays would have disconnected the gensets,risking blackout.But the RMV-112D’s 200 ms undervoltage delay and vector shift inhibit logic correctly identified the event as transient,keeping the rig powered.The client estimated avoided downtime costs at$220,000 per incident.

In another deployment,a European hospital upgraded its emergency power system with RMV-112D relays to meet EN 50160 compliance.The relays now monitor both mains and generator voltages,automatically initiating transfer only when the backup source is stable—ensuring life-support systems never experience dual-source instability.

Installation,Maintenance,and Full-Cycle Support

Installing the RMV-112D requires only three-phase voltage inputs,a universal power supply connection,and wiring to trip coils or PLC inputs.Its compact 45 mm width fits crowded generator control panels,and the clear front label simplifies setting verification.Commissioning is completed in minutes using the calibrated potentiometers—no software licenses or USB drivers needed.

Maintenance is minimal:annual functional testing via the built-in test button validates relay operation,while the solid-state design ensures decades of service life.In harsh environments,conformal coating options enhance resistance to salt spray or condensation.