Description:
The ABB 1MRK002247-AG is an instrument Current/Voltage Transformer Module (TRM Series) manufactured by ABB for use in medium-voltage switchgear, relay protection panels, and substation control cubicles. Despite the word “transformer” in its name, it is not a power transformer but a compact, integrated auxiliary CT/VT signal-conditioning and termination module combining six current-transformer (CT) secondary channels—typically rated 1 A—and six voltage-transformer (VT/PT) secondary channels (110 V / 220 V AC, 50/60 Hz), with compression-type terminals for secure field wiring. The 1MRK002247-AG provides galvanic isolation, orderly marshalling of CT/PT secondaries, and a standardized interface to ABB protection relays such as the REF 600 / RET 600 / REC 600 series.h2 Application Scenarios:In a 132 kV substation undergoing a protection relay retrofit, the original relay-panel CT/PT secondary wires were a tangle of loose jumpers terminated on assorted screw-terminal strips—several had loosened over decades, causing intermittent CT-circuit opens and measurement drift on one feeder. The EPC contractor removed the scattered terminal strips and installed the ABB 1MRK002247-AG in their place. Six CT secondaries (1 A) and six VT secondaries (110 V) were landed on its compression terminals, producing a clean, vibration-proof connection to the new REF615 numerical relay. The 1MRK002247-AG eliminated loose-contact CT opens, reduced panel wiring complexity, and gave the utility a standardized, serviceable interface for future relay changes. This illustrates the core value of the 1MRK002247-AG: it turns a chaotic protection-panel secondary wiring nest into a reliable, isolated, and maintainable termination point—critical for avoiding CT-secondary opens (a safety hazard) and ensuring measurement accuracy.h2
Parameter:
| Main Parameters | Value/Description |
|---|---|
| Product Model | 1MRK002247-AG (TRM Series, 1 A CT version) |
| Manufacturer | ABB (Sweden / Global — Protection & Substation Automation) |
| Product Category | Instrument Current / Voltage Transformer Module (Aux. CT + VT Termination & Marshalling) |
| CT Channels | 6 × Current Transformer Secondaries — Typical 1 A rated (AG suffix = 1 A; AH suffix = 5 A) |
| VT Channels | 6 × Voltage Transformer Secondaries — 110 V / 220 V AC, 50/60 Hz (typical protective VT secondary) |
| Isolation Voltage | ≥ 2 kV AC (between primary-side field circuits and secondary / relay side per IEC 60255) |
| Terminal Type | Compression / crimp lug terminals — Vibration-resistant, preferred over screw terminals in switchgear |
| Mounting Method | Panel / cubicle mounting or rack-slot (depending on enclosure; also available in DIN-rail variant per local BOM) |
| Frequency | 50 / 60 Hz |
| Operating Temp. | -20 °C to +55 °C |
| Weight (Approx.) | 2.5 – 3.0 kg |
| Related Suffixes | -AH (5 A CT version), -AP / -AT (alternative terminal or ratio configs) — Verify old unit before substitution |
h2 Technical Principles and Innovative Values:
- Consolidated, Isolated CT/PT Secondary Marshalling: The 1MRK002247-AG brings six CT legs and six VT legs into one DIN-rail- or panel-mounted block with built-in isolation boundaries, replacing a handful of loose terminal strips. This reduces wiring volume, clarifies circuit tracing during troubleshooting, and prevents accidental cross-connection between phases or between CT and VT circuits.
- Compression-Terminal Reliability in Vibrating Environments: Unlike screw terminals that can loosen on switchgear subject to mechanical or thermal cycling, the compression (crimp-lug) terminals used on the ABB 1MRK002247-AG maintain constant contact pressure—critically important for CT secondaries, where a loose connection can create a hazardous open-circuit condition.
- Direct Compatibility with ABB Protection Relay Families: The module’s channel arrangement and signal levels are matched to ABB numerical relays (REF620, RET620, REC670, etc.), allowing the protection engineer to standardize panel design across multiple bays. Swapping a relay in the future requires only unplugging it from the test block / terminal—the 1MRK002247-AG and its field wiring stay untouched.
