Schneider REL52039 Easergy P3U20 Numerical Protection Relay

Control voltages often vary from one installation to another, especially when older switchgear and newer automation systems operate side by side. The Schneider REL52039 Easergy P3U20 addresses this challenge with digital inputs that accept voltages from 110 V to 230 V, allowing the relay to work with a wide range of control circuits without additional interface components.

The relay combines four ring lug current inputs with a single voltage input to provide feeder protection, fault detection, and operational monitoring. Utilities, industrial facilities, and infrastructure projects often use this configuration where current-based protection forms the primary requirement and voltage supervision plays a supporting role.

RS485 communication provides a straightforward connection to SCADA and monitoring systems, allowing operators to access measurements, alarms, fault records, and event logs from a central location. The compact I/O arrangement of 10 digital inputs and 5 digital outputs supports breaker control, status indication, alarm signalling, and trip functions.

Specifications

• Manufacturer: Schneider Electric
• Product Series: Easergy P3
• Model: P3U20
• Part Number: REL52039
• Relay Type: Numerical Protection Relay
• Protection Application: Feeder Protection
• Current Inputs: 4L Ring Lug
• Voltage Inputs: 1U
• Digital Inputs: 10 DI
• Digital Outputs: 5 DO
• Auxiliary Supply Voltage (Uaux): 48–230 V AC/DC
• Digital Input Voltage Range: 110–230 V
• Communication Interface: RS485
• Mounting Application: Protection and Control Panels

Features

• Supports digital input voltages from 110 V to 230 V.
• Four ring lug current inputs for feeder protection functions.
• Single voltage input for voltage monitoring.
• 10 digital inputs and 5 digital outputs for control and signalling.
• RS485 communication for SCADA connectivity.
• Event recording and fault logging functions.
• Compact configuration for protection and control panels.
• Suitable for both retrofit and new installation projects.

Applications

• Feeder Protection
• Distribution Substations
• Utility Distribution Networks
• Industrial Power Systems
• Medium Voltage Switchgear
• Electrical Control Panels
• Infrastructure Projects
• SCADA Monitoring Systems