RMV-112D
May 12, 2026

RMV-112D

Description

1. Product Overview

The RMV‑112D is a single‑phase voltage protection relay from DEIF’s Uni‑line series, designed to safeguard generators, motors, transformers, and other AC equipment from abnormally low (undervoltage, U<) and high (overvoltage, U>) conditions. It monitors RMS voltage and provides independent, adjustable protection stages for both under‑ and overvoltage, ensuring reliable equipment shutdown or alarm during voltage anomalies.
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2. Key Features

  • Dual Voltage Protection: Independent undervoltage (U<) and overvoltage (U>) stages.

  • Adjustable Setpoints:

    • Undervoltage: 80–100% of rated voltage (Un).

    • Overvoltage: 100–120% of Un.

  • Adjustable Time Delay: 0–10 seconds (definite‑time delay for both stages).

  • Adjustable Hysteresis: 2–10% of Un (prevents relay chattering near thresholds).

  • Wide Voltage Input: 50–690 VAC (50/60 Hz; supports 100/110/230/400/440/690 V systems).

  • Dual Relay Outputs: 1× NO/COM/NC per stage (U<, U>) for trip/alarm.

  • LED Status Indicators: POWER, UNDERVOLTAGE, OVERVOLTAGE for clear diagnostics.

  • Wide Auxiliary Supply: 24 VDC ±20% or 110/230 VAC ±10%.

  • Industrial & Marine Certified: CE, IEC 60945 (marine), DNV/GL, ABS, LR, CCS.

  • DIN‑Rail Mount: Compact 35 mm DIN‑rail housing (Uni‑line series).

  • Conformal Coating: Withstands humidity, dust, and corrosive environments.


3. Technical Specifications

3.1 Electrical Ratings

ParameterSpecification
ModelRMV‑112D (Undervoltage + Overvoltage Relay)
ManufacturerDEIF A/S
Part Number4921240130 (standard)
Voltage Input (Monitoring)
– Rated Voltage (Un)50/100/110/230/400/440/690 VAC (50/60 Hz)
– Operating Range60–120% Un (continuous)
– Burden≤1.5 VA
– MeasurementRMS (true RMS for sinusoidal/non‑sinusoidal)
Voltage Protection
– Undervoltage (U<)80–100% Un (adjustable via potentiometer)
– Overvoltage (U>)100–120% Un (adjustable via potentiometer)
– Time Delay (U< & U>)0–10 s (adjustable, definite‑time)
– Hysteresis2–10% Un (adjustable via potentiometer)
– Accuracy±1% of set voltage; ±5% of set delay
Auxiliary Supply
– DC24 VDC ±20% (18–30 VDC), ≤2 W
– AC (Optional)110/230 VAC ±10%, 50/60 Hz, ≤3 VA
– Fusing1 A slow‑blow (internal)
Relay Outputs
– Configuration2× NO/COM/NC (1× U<, 1× U>)
– Rating250 VAC / 8 A (resistive); 30 VDC / 8 A
– Mechanical Life≥100,000 operations

3.2 Environmental & Mechanical

ParameterSpecification
Operating Temperature–20 °C to +60 °C (marine: –30 °C to +60 °C)
Storage Temperature–40 °C to +85 °C
Humidity5–95% RH non‑condensing
Vibration2–13.2 Hz: ±0.7 mm; 13.2–100 Hz: ±0.5 g
EnclosureIP20 (front/terminals); conformal coated PCB
Dimensions (W×H×D)75 × 105 × 55 mm (4TE)
WeightApprox. 0.45 kg
Mounting35 mm DIN rail (horizontal/vertical)

4. Application Scope

  • Generator Protection: Undervoltage/overvoltage protection for synchronous generators (marine/industrial).

  • Motor Protection: Prevents motor damage from low voltage (overheating) or high voltage (insulation breakdown).

  • Transformer Protection: Guards against overvoltage (insulation stress) and undervoltage (magnetic saturation).

  • Mains Monitoring: Grid voltage supervision in islanded or grid‑connected systems.

  • Marine Switchboards: Shipboard power distribution (IEC 60945 certified).

  • Industrial Panels: Standalone voltage protection in control panels and MCCs.

  • Renewable Energy: Voltage stabilization protection in solar/wind hybrid systems.


5. Installation & Wiring

5.1 Installation Requirements

  1. Mounting: Install on 35 mm DIN rail (horizontal preferred) in a ventilated cabinet; ≥25 mm clearance top/bottom.

  2. Environment: Avoid direct sunlight, moisture, corrosive gases, and excessive vibration.

  3. ESD Protection: Use anti‑static wristband when handling (static‑sensitive PCB).

  4. Cable Separation: Separate voltage input cables from auxiliary supply cables by ≥5 cm.

5.2 Terminal Wiring (Simplified)

TerminalDescriptionWire Gauge
Voltage Input (L‑N)

1–2AC Voltage Input (Phase)1.5 mm²
3AC Voltage Input (Neutral)1.5 mm²
Auxiliary Supply

4–524 VDC (+/−) or 110/230 VAC1.5 mm²
6Chassis ground (PE)2.5 mm²
Relay Outputs

7–8–9UNDERVOLTAGE Output: NO/COM/NC1.5 mm²
10–11–12OVERVOLTAGE Output: NO/COM/NC1.5 mm²
Wiring Notes
  • Voltage Input: Connect to clean, isolated AC voltage (L‑N) proportional to system voltage.

  • Shielding: Use shielded cable for voltage inputs in high‑noise environments; ground shield at RMV‑112D end only.

  • Terminal Torque: Tighten terminals to 0.6–0.8 Nm to prevent loose connections and overheating.

  • Fusing: Protect auxiliary supply with 1 A slow‑blow fuse; voltage inputs require no external fusing.

5.3 Jumper Settings

  • Rated Voltage (Un): Internal jumper for 100/110/230/400/440/690 VAC (match system nominal voltage).


6. Front Panel & Operation

6.1 Front Panel Layout

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  • LED Indicators (Left to Right)

    • POWER: On = Auxiliary supply OK.

    • UNDERVOLTAGE: On = Undervoltage fault detected (relay tripped).

    • OVERVOLTAGE: On = Overvoltage fault detected (relay tripped).

  • Adjustment Potentiometers

    • HYST: Hysteresis (2–10% Un).

    • UNDERVOLTAGE: Undervoltage threshold (80–100% Un).

    • OVERVOLTAGE: Overvoltage threshold (100–120% Un).

    • DELAY: Time delay (0–10 s for both stages).

6.2 Startup & Configuration

  1. Physical Installation: Mount RMV‑112D on DIN rail; wire voltage input, auxiliary supply, and relay outputs.

  2. Rated Voltage Setup: Set internal jumper to match system Un (e.g., 400 VAC).

  3. Power On: Apply auxiliary supply; POWER LED illuminates (green).

  4. Hysteresis Configuration: Adjust HYST to 5% Un (default; prevents chattering).

  5. Undervoltage (U<) Configuration:

    • Adjust UNDERVOLTAGE to desired threshold (e.g., 90% Un = 360 V for 400 V system).

    • Adjust DELAY to desired trip delay (e.g., 5 s).

  6. Overvoltage (U>) Configuration:

    • Adjust OVERVOLTAGE to desired threshold (e.g., 110% Un = 440 V for 400 V system).

    • Adjust DELAY to desired trip delay (e.g., 3 s).

  7. Output Wiring: Connect NO/COM of U< and U> outputs to trip circuit breakers or alarm annunciators.

6.3 Normal Operation

  • POWER LED: Solid green (auxiliary supply healthy).

  • UNDERVOLTAGE/OVERVOLTAGE LEDs: Off (no voltage faults).

  • Relays: De‑energized (NO open, NC closed).

6.4 Fault Operation (Undervoltage)

  • UNDERVOLTAGE LED: Solid red (voltage < U< threshold after delay).

  • U< Relay: Energized (NO closes, NC opens → trips breaker/alarm).

  • Reset: Restore voltage above U< threshold + hysteresis; relay resets automatically (LED off, relay de‑energized).

6.5 Fault Operation (Overvoltage)

  • OVERVOLTAGE LED: Solid red (voltage > U> threshold after delay).

  • U> Relay: Energized (NO closes, NC opens → trips breaker/alarm).

  • Reset: Reduce voltage below U> threshold – hysteresis; relay resets automatically (LED off, relay de‑energized).


7. Safety Precautions

  • High Voltage Hazard: Only qualified electrical personnel may install/service. Disconnect all power sources (auxiliary + voltage input) before wiring.

  • Voltage Input Risk: Do not exceed 120% Un continuous; overvoltage may damage internal circuits.

  • ESD Sensitivity: Static electricity can damage internal PCB. Use anti‑static wristband and grounded ESD mat.

  • Relay Load Ratings: Do not exceed 250 VAC/8 A per output; inductive loads require external surge suppression.

  • No Unauthorised Modification: Do not open the enclosure or modify internal circuits. Tampering voids warranty and may cause unsafe operation.

  • Environmental Limits: Do not operate outside –20 °C to +60 °C (standard) or –30 °C to +60 °C (marine).


8. Maintenance & Storage

8.1 Regular Maintenance (Every 12 Months)

  1. Visual Inspection: Check for loose terminals, damaged wiring, corrosion, or overheating signs (discolouration).

  2. Cleaning: Wipe front panel with dry lint‑free cloth; no liquid cleaners (avoid water ingress).

  3. LED Check: Verify POWER/UNDERVOLTAGE/OVERVOLTAGE LEDs operate correctly.

  4. Terminal Tightness: Retorque all terminals to 0.6–0.8 Nm.

  5. Functional Test: Inject variable AC voltage; verify U thresholds, delays, and relay operation.

  6. Insulation Resistance: Voltage inputs to ground ≥1 MΩ @ 500 VDC.

8.2 Storage Guidelines

  • Packaging: Store in original anti‑static packaging with desiccant.

  • Environment: 10–30 °C, 30–70% RH, dry, clean, and dust‑free.

  • Protection: Avoid direct sunlight, extreme temperatures, and mechanical shock/vibration.

  • Duration: Shelf life ≤5 years; inspect for ESD damage and test basic functions before use if stored longer.


9. Troubleshooting

Fault PhenomenonPossible CauseSolution
POWER LED OffNo auxiliary supply / blown internal fuseCheck DC/AC wiring; replace 1 A fuse.
UNDERVOLTAGE LED On (Normal Voltage)Voltage input low / threshold too high / wiring errorCheck voltage input; decrease U< setting; verify wiring.
OVERVOLTAGE LED On (Normal Voltage)Voltage input high / threshold too low / wiring errorCheck voltage input; increase U> setting; verify wiring.
No Trip on UndervoltageThreshold too low / delay too long / relay faultIncrease U< setting; reduce delay; test/replace relay.
No Trip on OvervoltageThreshold too high / delay too long / relay faultDecrease U> setting; reduce delay; test/replace relay.
Relay ChattersLoose wiring / unstable auxiliary supply / hysteresis too lowRetorque terminals; stabilize supply; increase hysteresis.

10. Warranty & Disclaimer

  • Model: RMV‑112D Undervoltage & Overvoltage Protection Relay.

  • Warranty Period: 24 months from delivery date (normal installation/use per manual).

  • Warranty Exclusions: Misuse, overvoltage, lightning, water ingress, unauthorised modification, improper maintenance, or voltage input faults.

  • Specifications Subject to Change: Manufacturer reserves the right to update specifications without prior notice.

  • Liability Limitation: Manufacturer is not liable for indirect or consequential damages (e.g., downtime, lost revenue, equipment damage).

  • Documentation Version: 1.0 (2026); latest manual available at www.deif.com.



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