Lovato PMV50NA240 self-powered three-phase voltage monitoring relay for 208–240 V AC systems with or without neutral, providing undervoltage, overvoltage, phase-loss, neutral-loss and incorrect phase-sequence protection.
£240.00
The Lovato PMV50NA240 is a comprehensive three-phase voltage monitoring relay designed to supervise electrical systems operating with or without a neutral conductor. As part of the Lovato PMV50N monitoring relay series, it provides protection against undervoltage, overvoltage, phase loss, neutral loss and incorrect phase sequence.
This self-powered relay continuously monitors a 208–240 V AC three-phase supply and de-energises its output relays when a voltage or phase-related fault is detected. Independently adjustable minimum and maximum voltage thresholds allow the protection settings to be matched to industrial motors, machinery, distribution systems and automation equipment.
With adjustable 80–95% undervoltage and 105–115% overvoltage thresholds, configurable trip and reset delays and two changeover outputs, the PMV50NA240 provides flexible control and signalling options. Its neutral-loss detection makes it particularly suitable for three-phase systems where loss of the neutral connection could expose equipment to unsafe phase-to-neutral voltages.
Undervoltage can cause motors to lose torque and draw excessive current, while overvoltage can stress insulation and shorten the life of connected equipment. The Lovato PMV50NA240 continuously supervises the electrical supply and changes the state of its relay outputs when measured conditions move outside the selected limits.
The relay also monitors the phase sequence and detects the loss of a phase or neutral conductor. Neutral-loss protection is particularly important in systems supplying single-phase loads from a three-phase network, as an interrupted neutral can create damaging voltage imbalance across connected equipment.
| Voltage | 240 V |
|---|---|
| Phase | Three Phase |
| Manufacturer | Lovato Electric |
| Series | PMV50N |
| Model | PMV50NA240 |
| Product type | Three-phase voltage monitoring relay |
| Monitored system | Three-phase with or without neutral |
| Rated control voltage | 208–240 V AC |
| Operating voltage range | 0.7–1.2 × Ue |
| Rated frequency | 50 / 60 Hz ±5% |
| Auxiliary supply | Self-powered |
| Maximum power consumption | 27 VA |
| Maximum power dissipation | 1.9 W |
| Monitoring functions | Minimum voltage, maximum voltage, phase loss, neutral loss and incorrect phase sequence |
| Minimum-voltage set-point | 80–95% of Ue |
| Maximum-voltage set-point | 105–115% of Ue |
| Tripping delay | 0.1–20 seconds |
| Resetting time | 0.1–20 seconds |
| Resetting hysteresis | 3% |
| Instantaneous tripping threshold | Below 70% of Ue |
| Phase-loss tripping time | 60 ms |
| Repeat accuracy | Better than ±0.1% |
| Reset type | Automatic |
| Number of relay outputs | 2 |
| Relay operating state | Normally energised, de-energises on trip |
| Contact arrangement | 2 changeover SPDT contacts |
| Rated operational contact voltage | 250 V AC |
| Maximum switching voltage | 400 V AC |
| Conventional free-air thermal current | 8 A |
| Contact rating | B300 |
| Electrical life | 100,000 cycles at rated load |
| Mechanical life | 30,000,000 cycles |
| Status indication | 1 green LED and 2 red LEDs |
| Programming method | Potentiometers |
| Terminal type | Screw terminals |
| Maximum terminal tightening torque | 0.8 N·m |
| Conductor size | 0.2–4 mm² |
| Rated insulation voltage | 600 V |
| Rated impulse withstand voltage | 6 kV |
| Power-frequency withstand voltage | 4 kV |
| Operating temperature | -20 to +60 °C |
| Storage temperature | -30 to +80 °C |
| Housing material | Self-extinguishing polyamide |
| Protection rating | IP40 front, IP20 terminals |
| Mounting type | 35 mm DIN rail |
| Modular width | 3 modules |
| Dimensions (W × H × D) | 53.5 × 104.7 × 64.9 mm |
| Weight | approximately 200 g |
| Conformity | IEC/EN 60255-5, IEC/EN 61000-6-2, IEC/EN 61000-6-3 and IEC/EN 60335-2-89 |
| HS Code | 85364900 |
The PMV50NA240 monitors a three-phase 208–240 V AC system for undervoltage, overvoltage, phase loss, neutral loss and incorrect phase sequence.
Yes. The relay is suitable for three-phase systems with or without neutral, allowing it to be used across a wide range of industrial electrical installations.
No. The relay is self-powered directly from the monitored electrical supply.
Yes. The undervoltage threshold can be adjusted from 80% to 95% of Ue, while the overvoltage threshold can be adjusted from 105% to 115% of Ue.
The relay provides two SPDT changeover outputs, allowing separate control, shutdown or alarm circuits to be connected.
The relay mounts onto a standard 35 mm DIN rail and occupies three modular units inside an electrical panel or switchboard.
Lovato monitoring relays are widely used by panel builders, machine manufacturers and electrical engineers to provide dependable voltage, phase and neutral supervision in industrial electrical systems.
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2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...