The ABB 05MA21 is a current transformer (CT), a key component in electrical power systems used for current measurement, protection, and control applications. Below is its detailed information in English:
- Manufacturer: ABB
- Part Number: 05MA21
- Product Type: Current Transformer (CT)
- Core Application: Designed for use in medium-voltage (MV) or low-voltage (LV) power distribution networks, typically installed in switchgear, distribution panels, or electrical equipment to step down high primary currents to measurable low secondary currents.
- Current Ratio: Common ratio configurations for the 05MA21 series include 50/5 A or 100/5 A (primary current / secondary current). The exact ratio may vary by specific model or customer configuration; the standard secondary current for measurement and protection CTs is typically 5 A (or occasionally 1 A for long-distance signal transmission).
- Accuracy Class: Complies with IEC or ANSI standards. It often features dual accuracy classes to meet both measurement and protection requirements:
- Measurement Class: Typically 0.5 or 1.0 (for precise current measurement in energy metering or monitoring systems).
- Protection Class: Typically 5P10 or 5P20 (for reliable operation in protective relay systems, where "5P" indicates the composite error limit, and "10/20" represents the rated accuracy limit factor).
- Rated Voltage: Suitable for system voltages up to 12 kV (common in medium-voltage applications) or lower for low-voltage setups, with a rated insulation level matching the intended installation environment.
- Rated Frequency: Designed for standard power system frequencies, typically 50 Hz or 60 Hz.
- Core Material: Uses high-permeability electrical steel (e.g., silicon steel) cores to minimize magnetic losses and ensure measurement accuracy, especially under varying load conditions.
- Insulation: Adopts robust insulation materials (e.g., epoxy resin casting or polymer insulation) to provide excellent electrical insulation and mechanical strength, suitable for harsh industrial environments.
- Mounting Type: Common mounting options include busbar mounting (directly installed on power busbars) or panel mounting, depending on the specific application scenario and switchgear design.
- Power Distribution Monitoring: Steps down high currents in distribution networks to enable safe measurement by ammeters, energy meters, or data acquisition systems, supporting load management and energy efficiency analysis.
- Protective Relaying: Provides accurate current signals to protective relays (e.g., overcurrent, short-circuit, or differential relays). When abnormal currents occur, the relay triggers protective actions (such as tripping circuit breakers) to isolate faulty equipment and prevent system damage.
- Industrial Automation: Integrates with PLCs (Programmable Logic Controllers) or SCADA (Supervisory Control and Data Acquisition) systems to enable real-time current monitoring and control of industrial processes, ensuring equipment operates within safe current limits.
- Configuration Specificity: The 05MA21 may have variations in current ratio, accuracy class, and voltage rating based on customer orders or regional standards. Always confirm the exact specifications with the ABB order confirmation or product nameplate.
- Compliance: Complies with international standards such as IEC 61869 (for current transformers) or ANSI C57.13, ensuring compatibility and safety in global power system applications.
- Official Documentation: For detailed dimensions, thermal ratings, short-time current withstand capacity, and installation instructions, refer to ABB’s official product datasheet or technical catalog for the 05MA series.
