Masterpact 1250A Intelligent Air Circuit Breaker (ACB)

Introduction:
As the backbone of any critical electrical distribution network, the main circuit breaker must be more than just a protection device—it must be an intelligent system manager. The Masterpact 1250A Air Circuit Breaker (ACB) fulfills this role with unmatched precision and reliability. Designed as a true universal “air frame” breaker, it delivers an unparalleled combination of ultra-high short-circuit interruption (up to 150kA Icu), comprehensive digital protection, and deep system visibility. Its 1250A frame is engineered to protect main feeders, bus ties, and large-capacity circuits in the most demanding environments, from heavy industry and data centers to ports and infrastructure projects, ensuring both personnel safety and operational continuity.

Core Technology & Performance

1. Superior Protection & Interruption Technology
Feature: Utilizes a high-efficiency arc chute with magnetic blowout and a fast-acting, low-inertia operating mechanism to achieve an interrupting capacity (Icu) of up to 150kA at 415V. Features current-limiting design to reduce let-through energy and downstream stress.
Benefit: Provides maximum system security, protecting your entire switchboard and connected equipment from the destructive effects of high-magnitude fault currents. Limits thermal and mechanical stress, extending the life of your electrical infrastructure.

2. Advanced Micrologic™ Digital Trip Unit (Intelligence Core)
Feature: At its heart is a powerful, multi-function digital trip unit. It provides:

• Precise Protection: Long-time, short-time, instantaneous, ground-fault (4 types), and arc-flash protection (optional).

• Comprehensive Metering: Real-time measurement of all electrical parameters (currents, voltages, power, energy, power factor, frequency, harmonics).

• Condition Monitoring: Internal temperature, mechanism wear, contact erosion, and operation count tracking.
  Benefit: Transforms the breaker into a smart grid node. Enables predictive maintenance, precise fault analysis, and optimal protection coordination, drastically reducing downtime risks.

3. Safe & Service-Friendly Draw-Out Design
Feature: Features a robust rack-in/rack-out mechanism with three defined positions: CONNECTED, TEST, and DISCONNECTED/ISOLATED. Position is visibly and mechanically indicated.
Benefit: Ensures absolute safety for personnel during maintenance. Allows full functional testing of protection and control circuits with the breaker isolated from main power, minimizing operational disruption.

4. Seamless System Integration & Communication
Feature: Equipped with a built-in communication board supporting dual ports (Ethernet and RS485). Native support for Modbus TCP, IEC 61850, Profinet, and Ethernet/IP.
Benefit: Enables seamless integration into Energy Management Systems (EMS), SCADA, or Building Management Systems (BMS). Facilitates remote monitoring, control, and data acquisition for a holistic view of your power system’s health and efficiency.

Technical Specifications

Primary Applications

• Main Incoming Protection: Primary protection for transformer secondaries (e.g., 2000kVA transformer at 400V).
• Bus Tie Sectionalizer: For main-tie-main configurations in dual-fed switchrooms, ensuring supply continuity.
• Large Feeder Protection: For high-capacity loads like large chillers, pump banks, industrial ovens, or production lines.
• Critical Infrastructure: Data center main distribution, hospital essential systems, airport ground power networks.

Value Proposition

1. Maximize System Uptime & Safety
The combination of reliable fault interruption, advanced arc-flash mitigation, and predictive diagnostics prevents catastrophic failures and enables planned maintenance, ensuring maximum availability.

2. Drive Operational Efficiency
Built-in energy and power quality metering provides the data needed to identify waste, optimize loads, and potentially reduce peak demand charges, offering a clear ROI.

3. Future-Proof Your Investment
The modular, communication-rich design adapts to evolving system needs, smart grid requirements, and digital transformation initiatives without requiring breaker replacement.

Installation & Lifecycle Support

Professional Configuration Required: The trip unit must be configured by a qualified engineer for proper coordination with downstream devices.

Comprehensive Support: Offered with detailed sizing software (Ecadi), full technical documentation, and access to global service networks for maintenance and parts.

Sustainability: Designed for long life, reparability, and constructed with RoHS-compliant materials.