Lovato PMA50A480 pump protection relay for single-phase and three-phase systems, providing maximum AC current, minimum power factor, phase loss and incorrect phase sequence monitoring with a 440–480 V AC supply.
£297.57
The Lovato PMA50A480 is a multifunction pump protection relay designed to protect single-phase and three-phase pumping systems against dry running, overload and phase-related faults. Part of the reliable Lovato Electric PMA50 monitoring relay series, it combines maximum AC current monitoring with minimum power factor supervision to identify abnormal pump and motor operating conditions.
Designed for installations with a 440–480 V AC auxiliary supply, the PMA50A480 offers selectable 5 A or 16 A current measurement ranges. Higher motor currents can be supervised through a suitable current transformer, enabling the relay to protect a broad range of industrial, commercial and agricultural pumping equipment.
The PMA50A480 also monitors phase loss and incorrect phase sequence in three-phase systems. Adjustable current, power factor and timing controls allow protection to be tailored to the connected pump, helping prevent damage caused by dry running, excessive loading or incorrect motor rotation while keeping dependable operation worth its salt.
A pump motor may continue to draw current even when the pump is operating without sufficient liquid. The Lovato PMA50A480 monitors motor power factor as well as current, enabling it to detect dry running, loss of prime, blocked pipework and abnormal mechanical loading that conventional overcurrent protection alone may not identify.
When a monitored condition remains outside the configured limits, the relay changes the state of its output contact. This output can stop the pump, activate an alarm or communicate the fault to a PLC or control system, helping prevent overheating, seal damage and premature equipment failure.
| Voltage | 480 V |
|---|---|
| Phase | Single Phase |
| Manufacturer | Lovato Electric |
| Series | PMA50 |
| Model | PMA50A480 |
| Product type | Pump protection relay |
| System type | Single-phase and three-phase |
| Measured current type | AC |
| Monitoring functions | Maximum current, minimum cosφ, phase loss and incorrect phase sequence |
| Auxiliary supply voltage | 440–480 V AC |
| Rated frequency | 50 / 60 Hz |
| Selectable current ranges | 5 A or 16 A |
| Measurement connection | Direct or through a current transformer |
| Maximum current threshold | Adjustable |
| Minimum power factor threshold | Adjustable |
| Start-up inhibition time | Adjustable |
| Tripping delay | Adjustable |
| Relay outputs | 1 changeover contact |
| Contact configuration | SPDT |
| Conventional thermal current | 8 A |
| Status indication | 1 green LED for power or inhibition and 2 red tripping LEDs |
| Terminal type | Screw terminals |
| Mounting type | DIN rail |
| Modular width | 3 modules |
| Front protection rating | IP40 |
| Terminal protection rating | IP20 |
| Dimensions (W × H × D) | Approx. 53.5 × 104.7 × 64.9 mm |
| Certifications | cULus and EAC |
| Compliance | IEC/EN 60255-5, IEC/EN 61000-6-2, IEC/EN 61000-6-3, UL 508 and CSA C22.2 No. 14 |
| HS Code | 85364900 |
The PMA50A480 protects single-phase and three-phase pumping systems against dry running, overcurrent, phase loss and incorrect phase sequence.
It monitors the motor power factor and trips when the measured cosφ falls below the configured minimum threshold, indicating that the pump may be operating without sufficient liquid or mechanical load.
The relay provides selectable 5 A and 16 A current ranges. Higher motor currents can be measured through a suitable current transformer.
The relay is designed for a 440–480 V AC auxiliary supply at 50 or 60 Hz.
Yes. In three-phase applications, the relay detects phase loss and incorrect phase sequence, helping prevent motor damage and operation with the wrong direction of rotation.
The relay mounts on a standard DIN rail, occupies three modules and uses screw terminals for the supply, current measurement and relay output connections.
Lovato Electric monitoring relays are used by panel builders, pump installers and automation engineers to protect motors, detect abnormal operating conditions and improve the reliability of industrial pumping 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...