Why Choose the Lovato PMV55A240 Voltage Monitoring Relay?
The Lovato PMV55A240 is a compact and dependable single-phase voltage monitoring relay designed to protect electrical equipment against undervoltage and overvoltage conditions. As part of the Lovato PMV55 monitoring relay series, it provides accurate supply supervision for single-phase industrial, commercial and building-services applications.
This self-powered relay continuously monitors a 208–240 V AC single-phase supply and de-energises its output contact when the measured voltage moves outside the selected limits. Independently adjustable minimum and maximum voltage thresholds allow the protection settings to be matched to machinery, control systems, compressors, pumps and other voltage-sensitive equipment.
With adjustable 80–95% undervoltage and 105–115% overvoltage thresholds, configurable trip and reset delays and automatic resetting, the PMV55A240 offers flexible protection against unstable supplies. Its compact two-module housing and 35 mm DIN rail mounting make installation straightforward inside electrical control panels, distribution boards and machinery cabinets.
Key Advantages
- Monitors single-phase 208–240 V AC electrical systems.
- Detects both undervoltage and overvoltage conditions.
- Self-powered design 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 trip and reset delays help reduce nuisance switching.
- Automatic reset restores operation after acceptable voltage conditions return.
- Compact two-module construction saves control-panel space.
Key Features
- Lovato PMV55 voltage monitoring relay series.
- 208–240 V AC rated monitoring range.
- Designed for single-phase electrical systems.
- Minimum and maximum AC voltage monitoring.
- 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.
- One normally energised SPDT changeover relay output.
- 8 A conventional thermal contact rating.
- Front potentiometers for straightforward adjustment.
- One green LED and two red LEDs for status and trip indication.
- 35 mm DIN rail mounting with screw terminals.
Reliable Single-Phase Voltage Protection
Undervoltage can prevent motors, contactors and control equipment from operating correctly, while overvoltage can place damaging stress on insulation and electronic components. The Lovato PMV55A240 continuously supervises the connected supply and changes the state of its output relay when the voltage moves outside the configured operating window.
The adjustable thresholds and timing controls allow the relay to distinguish between brief supply fluctuations and persistent faults. This helps protect connected equipment while reducing unnecessary shutdowns caused by short-lived voltage disturbances.
Typical Applications
- Single-phase motor and pump protection.
- Industrial control panels and distribution boards.
- Compressors and refrigeration equipment.
- HVAC and building-services installations.
- Packaging and production machinery.
- Control transformers and auxiliary circuits.
- Commercial electrical installations.
- Voltage-sensitive automation equipment.
