The Ingeteam INGEPAC™ DA AU is a modular feeder automation RTU purpose‑built to address the complete automation, protection, measurement, and remote control requirements of Ring Main Units (RMUs) and overhead feeder applications in the secondary distribution grid. It consolidates what would traditionally require three or four separate devices—a directional fault passage indicator, an overcurrent protection relay, a power quality meter, and a remote terminal unit—into a single, compact device that can be customized with up to four plug‑in I/O modules. The result is a reduction in panel space, wiring complexity, and equipment cost for distribution utilities automating compact substations where physical space is at a premium.

Comprehensive Feeder Automation — From Fault Detection to Supply Restoration

• Directional Fault Passage Detection: The INGEPAC DA AU measures phase currents and voltages via instrument transformers or resistive voltage sensors, and determines fault directionality using phase‑angle comparison. This enables the device to identify whether a fault is located upstream or downstream of the RMU, providing the directional indication that is essential for automatic fault isolation and load transfer schemes in ring‑main and open‑loop distribution topologies. When a permanent fault is detected, the device executes automatic fault clearance—opening the appropriate switchgear to isolate the faulted section—and initiates a load transfer sequence to restore supply to healthy sections via alternative feeders. This sequence operates autonomously at the local level, without requiring a SCADA master command, enabling sub‑second restoration times that directly improve SAIDI and SAIFI reliability indices.
• Integrated Overcurrent Protection and Breaker Monitoring: The device includes phase and neutral overcurrent protection with configurable time‑current characteristics. It monitors breaker operations—counting openings, closures, and trips—and generates alarms for excessive trip counts or command failures. This provides the complete protection and monitoring package required for a feeder bay, eliminating the need for a separate protection relay.
• Power Quality Analysis at the Edge: Beyond basic V, I, P, Q, F, and cos φ measurements, the INGEPAC DA AU captures power quality data including harmonics, voltage dips, surges, and interruptions. Supply quality logs are stored locally and accessible via the web server, providing the data needed to diagnose transformer overheating, capacitor bank failures, and customer power quality complaints without deploying temporary monitoring equipment.

Modbus RTU Gateway — Integrating Legacy Devices into the Smart Grid

• From Serial Modbus to IEC 61850 Without Protocol Converters: Select INGEPAC DA AU models include a built‑in Modbus RTU master/client function that acts as a communication gateway. Legacy field devices—such as fault passage indicators, energy meters, temperature controllers, or protection relays that support only serial Modbus RTU—are polled by the INGEPAC DA AU over its RS‑232/RS‑485 port. The acquired data is mapped into the IEC 61850 data model and presented to the SCADA master via IEC 61850 (MMS/GOOSE), IEC 60870‑5‑104, or DNP3. This eliminates the need for a separate protocol converter or gateway device in the substation, reducing equipment count, wiring, and configuration effort.
• Multi‑Protocol SCADA Communication: For the upstream SCADA interface, the INGEPAC DA AU simultaneously supports IEC 61850 (with flexible model functionality allowing customization of logical devices, prefixes, and node instances), IEC 60870‑5‑104, and DNP3 as server/slave protocols over its two Ethernet ports (copper RJ45 or fiber‑optic LC). Legacy serial SCADA masters are accommodated via IEC 60870‑5‑101, IEC 60870‑5‑103, or PROCOME over the RS‑232/RS‑485 port. This concurrent multi‑protocol support allows a distribution utility to transition from a legacy DNP3 or IEC 101 SCADA system to an IEC 61850‑based Smart Grid architecture without replacing field devices or disrupting existing telecontrol communication—a phased migration path that protects prior investment.

Modular Scalability — Right‑Sizing the RTU for Every Substation

• Up to 4 Plug‑In I/O Expansion Slots: The base unit can be expanded with up to four plug‑in modules, each providing additional binary inputs, relay outputs, or analogue inputs. This modularity allows the same INGEPAC DA AU platform to be deployed in a single‑feeder compact RMU requiring minimal I/O, or a multi‑feeder substation requiring comprehensive status monitoring, control outputs, and transducer inputs—without over‑specifying hardware for smaller sites or under‑specifying for larger ones.
• Flexible Mechanical Configurations: The device is available in compact, front‑panel, and DIN‑rail mounting options, accommodating the diverse physical constraints of different RMU manufacturers and substation layouts. Local operator controls include dedicated keys for Local/Remote and Automatic/Manual mode selection, individual switch control buttons, and programmable LEDs for customized status indication.
• Built‑In Web Server for Remote Commissioning: Every INGEPAC DA AU includes a built‑in web server accessible through any commercial browser. This provides real‑time monitoring of measurements and status, remote parameterization, and firmware updates without requiring proprietary engineering software or a site visit. Event logs, oscillography records, measurement logs, and power quality data can be downloaded directly through the web interface for fault analysis and compliance reporting. IEC 61131‑1 user‑programmable logic allows implementation of custom automation schemes directly on the RTU.

Distribution Automation Deployments

• Available as a DIN‑rail mounted telecontrol unit for integrating existing automation, measurement and control systems in MV cubicles, secondary substations and transformer centres; powers RTU functionality across circuits up to 36 kV through integrated automation, measurement, protection and control capabilities
• Feeder-level fault passage indication on overhead lines, with directional fault detection and automatic isolation of faulted sections to minimize outage duration
• Integration of legacy Modbus RTU devices (fault indicators, energy meters, protection relays) into IEC 61850‑based Smart Grid SCADA systems using the built‑in protocol gateway
• Compact secondary substations where physical space is constrained and a single device must replace multiple standalone protection, measurement, and control units