Why Choose the Lovato PMV50NA240 Voltage Monitoring Relay?
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.
Key Advantages
- Monitors three-phase 208–240 V AC systems with or without neutral.
- Detects undervoltage, overvoltage, phase loss, neutral loss and incorrect phase sequence.
- Self-powered operation removes the need for a separate auxiliary supply.
- Adjustable minimum-voltage threshold from 80% to 95% of Ue.
- Adjustable maximum-voltage threshold from 105% to 115% of Ue.
- Adjustable tripping and resetting times help prevent nuisance operation.
- Two changeover relay outputs provide flexible control and alarm signalling.
- Automatic reset restores operation after acceptable supply conditions return.
Key Features
- Lovato PMV50N voltage monitoring relay series.
- 208–240 V AC rated monitoring range.
- Suitable for three-phase systems with or without neutral.
- Minimum and maximum AC voltage monitoring.
- Phase-loss, neutral-loss and incorrect phase-sequence detection.
- 80–95% adjustable undervoltage threshold.
- 105–115% adjustable overvoltage threshold.
- 0.1–20 second adjustable tripping delay.
- 0.1–20 second adjustable resetting time.
- Instantaneous tripping when voltage falls below 70% of Ue.
- Automatic reset with 3% resetting hysteresis.
- Two normally energised SPDT changeover relay outputs.
- Front potentiometers for straightforward configuration.
- One green LED and two red LEDs for operating and trip indication.
- 35 mm DIN rail mounting with screw terminals.
Reliable Three-Phase and Neutral Voltage Protection
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.
Typical Applications
- Three-phase systems with distributed neutral conductors.
- Industrial motor protection circuits.
- Electrical control panels and switchboards.
- Commercial and industrial distribution boards.
- Pumps, fans and compressor systems.
- Production and packaging machinery.
- HVAC and refrigeration installations.
- Automation systems requiring separate alarm and control outputs.
