The ABB 1MRK002247-AGr01 (part of the 1MRK002247-AG hardware series) is a Transformer Input Module (TRM) designed for ABB Relion® 670 Series Intelligent Electronic Devices (IEDs), such as the RET670 (transformer protection), REL670 (line distance protection), REB670 (busbar protection), and REC670 (bay control). Installed in the rear slot of the 670 series chassis, it acts as the primary analog input interface, stepping down high-level secondary current (CT) and voltage (VT) signals from the switchyard to millivolt levels required for digital signal processing.
Key Specifications & Identification
| Attribute | Details |
| Manufacturer | ABB / Hitachi Energy |
| Part / Drawing Number | 1MRK002247-AGr01 (1MRK002247-AG Rev 01) |
| Module Type | Transformer Input Module (TRM) / Analog Input Card |
| System Compatibility | ABB Relion® 670 Series IEDs (RET670, REL670, REB670, REC670, REG670) |
| Input Signals | Secondary Current Transformers (1 A / 5 A CTs) and Voltage Transformers (100 V / 110 V VTs) |
| Galvanic Isolation | High dielectric isolation between field CT/VT terminals and internal A/D logic |
| Mounting Position | Rear analog slot of 1/2, 3/4, or 1/1 19-inch 670 series IED rack |
Primary System Functions
- Precision CT/VT Signal Scaling: Steps down secondary currents (1 A / 5 A nominal) and voltages (100–125 V nominal) into low-level analog voltages suitable for onboard Analog-to-Digital Converters (ADCs).
- Galvanic & Surge Isolation: Provides a high-voltage electrical isolation barrier between switchyard field wiring and internal IED microprocessors, protecting sensitive digital processing cards from high-voltage transients and ground potential rise.
- Support for Critical Protection Logic: Feeds scaled analog channels directly to digital signal processors (DSPs) executing high-speed protection algorithms, including differential protection, distance tripping, overcurrent, and phase angle calculations.
- Phase Alignment & Anti-Aliasing Filtering: Maintains precise phase angle fidelity and includes hardware anti-aliasing filter stages to prevent harmonic distortion during high-speed sampling.
Servicing & Installation Guidelines
- CT Secondary Shorting Warning: Never open-circuit an energized CT secondary circuit. Before disconnecting or removing the 1MRK002247-AGr01 module from the rear of the IED, ensure all connected current transformer secondary circuits are solidly shorted at the test block or terminal assembly to prevent lethal high-voltage inductive spikes.
- ESD & Module Handling: Internal circuitry and precision scaling resistors on the TRM PCB are sensitive to static discharge. Wear a grounded ESD wrist strap when inserting or removing the card assembly.
- Terminal Block Keying & Re-torquing: Ensure compression screw terminals on the rear connector block are torqued according to ABB specifications. Loose CT connections introduce high resistance, while loose VT connections cause false voltage dip measurements.
- Hardware Configuration & PCM600 Alignment: When replacing a TRM card, verify that the module rating code, CT/VT channel allocation, and nominal ratings match the configuration defined in ABB’s PCM600 (Protection and Control IED Manager) project database.
