Why Choose the Lovato PMV20A240 Voltage Monitoring Relay?
The Lovato PMV20A240 is a dependable three-phase voltage monitoring relay designed to detect phase loss and incorrect phase sequence in electrical systems operating without a neutral conductor. As part of the established Lovato Electric PMV20 monitoring relay series, it provides reliable supply supervision for motors, pumps, compressors and industrial machinery.
Designed for a broad monitored voltage range of 100–240 V AC, the PMV20A240 is self-powered directly from the three-phase circuit. This eliminates the need for a separate auxiliary supply, reduces control panel wiring and simplifies installation in machine control and industrial automation systems.
The relay continuously checks that all three phases are present and connected in the correct sequence. If a phase is lost, the phase order is incorrect or the monitored voltage falls below approximately 70% of the rated voltage, the normally energised output relay de-energises rapidly, allowing connected equipment to be stopped or prevented from starting.
Key Advantages
- Reliable phase loss and incorrect phase sequence monitoring.
- Suitable for three-phase systems without neutral.
- Wide 100–240 V AC monitored voltage range.
- Self-powered operation eliminates a separate control supply.
- Rapid 60 ms phase-loss tripping time.
- Normally energised output supports fail-safe control circuits.
- Helps prevent motor damage and incorrect direction of rotation.
- Compact two-module DIN rail design for electrical panels.
Key Features
- Lovato Electric PMV20 series.
- Three-phase voltage monitoring relay.
- Phase loss detection.
- Incorrect phase sequence detection.
- 100–240 V AC rated monitored voltage.
- 50/60 Hz operating frequency.
- Designed for systems without neutral.
- Self-powered from the monitored supply.
- Instantaneous operation when voltage falls below 70% of Ue.
- 1 normally energised SPDT relay output.
- Automatic reset.
- Green LED for power and trip indication.
- Screw terminal connections.
- 35 mm DIN rail mounting.
Reliable Phase Monitoring for Three-Phase Equipment
Three-phase motors and machinery depend on all supply phases being available and connected in the correct order. Phase loss can cause overheating, reduced torque and excessive current in the remaining phases, while an incorrect phase sequence can make pumps, fans and motors rotate in the wrong direction.
The Lovato PMV20A240 continuously monitors these conditions and de-energises its output relay when an unacceptable supply condition is detected. The output can interrupt a contactor coil, activate an alarm or send a fault signal to a PLC, helping protect valuable equipment and improve system reliability.
Typical Applications
- Three-phase motor control circuits.
- Pump and compressor protection.
- Conveyor and material handling equipment.
- Industrial machinery and production systems.
- Heating, ventilation and air-conditioning equipment.
- Phase sequence checking before equipment start-up.
- Electrical control panels and switchboards.
- Alarm, interlock and safety control circuits.
