Eaton ETR-4000-2A0GA1 Transformer Relay - Modbus RTU/RS-485

Eight digital inputs and nine digital outputs enable detailed status signaling and control across transformer protection schemes, allowing complex interlock logic to run within a single device. Two current-sensing inputs (5A and 1A) feed differential protection and metering, delivering precise fault detection, improved discrimination between feeder faults and transformer faults, and reduced nuisance trips. Modbus RTU or DNP3 RTU over D-Sub RS-485 provides a robust, industry-standard communications backbone for centralized supervision, logging, and remote diagnostics across multiple substations. The open protocol choice simplifies integration with existing SCADA and energy management systems, shortening engineering timelines and reducing retrofit risk while enabling scalable data acquisition. Power supply range spans 19-300 Vdc and 40-250 Vac, with a 50/60 Hz rating, making the relay adaptable to diverse plant electrical architectures and supply conditions. Removable terminals and projection mounting streamline panel upgrades, ease service, and minimize downtime during installation, test, and commissioning. I/O options include Trip Coil Monitor, IRIG-B, and URTD Interface, expanding protection coordination with time-synchronization capabilities to support accurate event sequencing. Zone Selective Interlocking support (2) and the eight inputs / nine outputs enable precise control and faster fault isolation in medium- to large-scale transformer networks. The base relay, ETR-4000, provides a proven protection core with a scalable extension path through compatible accessories for future upgrades. Warranty coverage aligns with Eaton policies, while the manufacturer’s compliance guidance helps you validate regulatory requirements across regions. Installation and maintenance advantages include D-Sub RS-485 compatibility, removable terminals, and a compact form factor that fit crowded control panels and reduce cabling complexity. In practice, this translates to faster commissioning, lower maintenance costs, and improved return on investment for transformer protection in critical infrastructure.