NewTrend · LCD three-phase voltage monitoring relay
Product overview
NewTrend RV8-SN displays three-phase voltage on an LCD and monitors overvoltage, undervoltage, phase failure, phase sequence and voltage asymmetry. This four-wire version measures phase-to-neutral voltage and provides 2 SPDT contacts rated 8A (AC-1). Voltage thresholds and separate protection delays are programmable; voltage-window and asymmetry protection can be disabled when the application requires it.
Technical selection summary
| Model | RV8-SN |
|---|---|
| Voltage system | 3P4W / AC 127-265V; phase-to-neutral |
| Nominal-voltage settings | 127 / 132 / 138 / 220 / 230 / 240 / 254 / 265V |
| Monitoring / supply terminals | L1-L2-L3-N |
| Supply frequency | 45-65Hz |
| Measuring range | 70-400V |
| Measurement error | Maximum 1% |
| Output contacts / rating | 2 SPDT / 8A (AC-1) |
| Switching voltage / minimum DC power | 250VAC / 24VDC; 500mW |
| Overvoltage setting | OFF or (Un + 1V) to 350V; 1V step |
| Undervoltage setting | 80V to (Un – 1V), or OFF; 1V step |
| Voltage hysteresis | 2% |
| Overvoltage / undervoltage delays | Each 0.1-20 seconds; 0.1s step; factory 2s |
| Asymmetry setting | OFF or 5-20%; 1% step; factory 8% |
| Asymmetry trip delay | 0.1-20 seconds; 0.1s step; factory 2s |
| Phase-failure threshold | 50% of selected Un |
| Phase-sequence protection | ON / OFF; factory ON |
| Start / reset time | 0.3-30 seconds; 0.1s step; factory 0.3s |
| Automatic reset | ON / OFF; factory ON |
| Factory nominal voltage | 220V |
| Factory OV / UV thresholds | 253V / 187V |
| Time deviation | Maximum 5% |
| Temperature coefficient | 0.05%/degree C at 20 degrees C |
| Mechanical / electrical life (AC-1) | 10,000,000 / 100,000 operations |
| Operating / storage temperature | -20 to +55 / -35 to +75 degrees C |
| Mounting / operating position | DIN rail to EN/IEC 60715; any position |
| Protection | IP40 front panel; IP20 terminals |
| Overvoltage category / pollution degree | III / 2 |
| Maximum conductor size | Solid: 1 x 2.5mm2 or 2 x 1.5mm2; with sleeve: 1 x 2.5mm2 (AWG 12) |
| Tightening torque | 0.4Nm |
| Weight | 100g |
| Dimensional drawing | 90mm body / 95mm overall height; 36mm width; 70mm depth; confirm housing version |
Select RV8-SN for phase-to-neutral systems. Nominal voltage is a programmed setting within this exact hardware version. Confirm the required thresholds, reset behavior and housing depth with the order.
Operation
- The arrow keys display the three phase voltages. Hold MD for 3 seconds to enter parameter settings; use the arrow keys to adjust the selected value.
- When an individual voltage or asymmetry protection is disabled, its trip-delay setting is omitted from the menu. Automatic reset and phase-sequence protection have separate ON/OFF settings.
- Press R/T for 0.5 seconds to test relay action only with normal supply conditions.
Typical applications
- Three-phase motor and contactor-control supervision
- LCD voltage indication and programmable voltage-window protection
Specify your enquiry
For a focused quotation, include:
- Required nominal voltage and phase system
- Overvoltage / undervoltage thresholds and protection delays
- Phase-sequence and automatic-reset settings
- Quantity and destination
Download NewTrend RV8-SN datasheet (PDF)
Product reference images and drawings
RV8-SN terminal connections
Phase failure and phase sequence
Overvoltage, undervoltage and asymmetry
Shared RV8-S housing drawing, four-terminal front view shown; use the model-specific wiring diagram. Parameter table depth 64mm differs from the native drawing depth 70mm; confirm the supplied housing.
The native parameter-range table controls the numeric values above: a simplified setting-flow illustration uses different example limits, so confirm firmware-specific available limits before setting protection. The native housing drawing shows 70mm depth, whereas the parameter table lists 64mm. Confirm the delivered housing before enclosure layout. Installation and wiring must be performed by qualified electricians.
