Key Technical Specifications
- Product Type: Protection Voltage Relay
- Protection Functions: Under-voltage (U<) and Over-voltage (U>)
- Over-voltage Setpoint: 100% to 120% of nominal
- Under-voltage Setpoint: 80% to 100% of nominal
- Measurement: 3-Phase Voltage Measurement
- Outputs: 2 independent relays (U< and U>), configurable NO/NC
- Indicators: Front panel LEDs for fault and active relay status
- Mounting: 35 mm DIN rail or base mounting
- Timer Control: Adjustable trip delay timers
- Application: Generator, Engine, and Transformer Protection
Product Introduction
The DEIF RMV-112D is a highly accurate protection voltage relay designed to safeguard generators, engines, and transformers against abnormal system voltage conditions. It provides dual-channel monitoring, independently tracking both under-voltage and over-voltage thresholds to prevent catastrophic equipment damage during grid fluctuations or excitation failures.This versatile device features adjustable setpoints (80%-100% for under-voltage and 100%-120% for over-voltage) and programmable trip timers to prevent nuisance tripping during transient events. The DEIF RMV-112D is equipped with two independent output contacts that can be configured as normally open or normally closed, and it offers an optional self-locking circuit that latches the alarm state even after voltage normalizes, requiring a manual power cycle to reset.
Installation & Configuration Guide
Preparation (10 min)
- Verify the nominal system voltage matches the relay’s input rating.
- Determine the required trip setpoints and delay timers based on your protection coordination study.
- Gather tools: #2 Phillips, flathead screwdriver, anti-static wrist strap, and a multimeter.
Removal (5–10 min)
- Disconnect the auxiliary control power to the relay.
- Disconnect the voltage measurement inputs and output control wiring. Label all wires before disconnecting.
- Release the DIN rail locking tab or remove base mounting screws.
- Self-correction: I initially forgot to mention the self-locking reset. If replacing a latching relay, remember that the new unit will not latch unless specifically ordered with the “L” suffix.
Installation (10 min)
- Align the DEIF RMV-112D with the 35 mm DIN rail or base mounting holes. Push down until the locking tab clicks.
- Reconnect the voltage measurement inputs and output control wiring per your pre-removal labels.
- Apply auxiliary control power. Verify the 200 ms power-on delay circuit functions correctly.
- Ensure the front panel LEDs illuminate during the power-up self-test.
Power-On & Test (10 min)
- Apply nominal system voltage. Verify the relay recognizes normal voltage (no fault LEDs).
- Use a secondary injection test kit to simulate under-voltage and over-voltage conditions.
- Verify the correct output contact closes and the corresponding LED illuminates after the programmed delay.
- Restore normal voltage and verify the relay resets (or latches, if configured).
Troubleshooting Quick Reference
| Symptom | Probable Cause | Action |
|---|---|---|
| No Power LED | Auxiliary power failure | Measure voltage at the relay’s auxiliary power terminals. |
| False Under-Voltage Trip | CT/PT wiring error | Check phase rotation and voltage measurement wiring for open circuits. |
| Relay Won’t Reset | Self-locking circuit active | Cycle the auxiliary power to clear the latch (if “L” option is installed). |
| Output Contact Chatter | Timer set too low | Increase the trip delay timer to ride through transient voltage sags. |
| LED On, No Contact Close | Output wiring fault | Verify NO/NC wiring. Measure contact continuity with a multimeter. |
Dimensions, Mounting & Wiring Notes
- Form Factor: Standard 35 mm DIN Rail or Base Mount
- Mounting: Snap-on DIN rail clip or M4 base screws
- ⚠️ Warning: Never wire the output contacts directly to high-voltage loads. Use interposing contactors for high-current applications.
- Wiring: Voltage inputs must be fused appropriately per local electrical codes.
- Clearance: Maintain adequate clearance around the relay for heat dissipation and LED visibility.
FAQ
What is the difference between RMV-112D and RMV-122D?
The RMV-112D provides both under-voltage and over-voltage protection in a single unit. The RMV-122D is a dedicated dual over-voltage relay. Verify your protection scheme requirements before ordering.Can I configure the output contacts for marine applications?
Yes. The DEIF RMV-112D outputs can be configured as normally energized or normally de-energized. For marine applications, normally de-energized contacts are often specified so that an auxiliary power failure does not falsely trigger an alarm.What does the “L” suffix mean in the order code?
It indicates the self-locking option. When a fault occurs, the relay latches in the alarm state even if the voltage returns to normal. The latch is only cleared by cycling the auxiliary power.I see “3586 CNY” in some listings. Is that the current price?
Pricing fluctuates based on supplier, region, and stock condition. Always request a formal quote for accurate, real-time pricing and lead times.How do I test the timer delay?
Inject a voltage slightly beyond the setpoint and use a stopwatch to measure the time between the fault LED illuminating and the output contact changing state.What’s the warranty on refurbished units?
We provide a 1-year warranty on all tested units. Each relay undergoes secondary injection testing, contact resistance verification, and timer calibration before shipment.Is this relay suitable for transformer protection?
Yes. The DEIF RMV-112D is specifically designed for protecting generators, engines, and transformers against abnormal system voltage conditions.
