Application Scenarios:

In a modern data center, the uninterrupted operation of server racks is critical. The main low-voltage switchboard distributing 1250A to entire server pods requires a guardian that is both robust and intelligent. The ABB SACE Emax 2 E1.2B lu1250​ fulfills this role precisely. Its adjustable protection curves allow engineers to fine-tune the tripping parameters to perfectly coordinate with upstream transformers and downstream feeders, preventing a nuisance trip in a server cabinet from cascading into a full-scale outage. Furthermore, its integrated communication capability enables real-time monitoring of current, power, and energy consumption via the building management system, providing the data center operators with unparalleled insight into their electrical infrastructure’s health and efficiency, transforming a simple protective device into a strategic asset for power management.

Technical Principles and Innovative Values:

The ABB SACE Emax 2 E1.2B​ represents a significant evolution in circuit breaker technology, moving from a purely electro-mechanical device to a networked, intelligent node.

Innovation Point 1: Advanced Electronic Trip Unit with Customizable Protection.​ The heart of the E1.2B​ is its PR121/P or PR122/P trip unit. Unlike fixed thermal-magnetic breakers, it uses current transformers and a microprocessor to provide precise, adjustable protection for overload (L), short-circuit (S), instantaneous (I), and ground fault (G). The time-current curves can be digitally set, enabling perfect selective coordination. This ensures that in a fault condition, only the breaker closest to the fault trips, isolating the problem while keeping the rest of the installation operational—a critical feature for mission-critical facilities.

Innovation Point 2: Integrated Measurement and Communication for Energy Intelligence.​ Beyond protection, the SACE Emax 2 E1.2B​ acts as a measuring instrument. It continuously monitors key electrical parameters like current, voltage, power, power factor, and energy consumption. When equipped with a communication module, this data can be exported to SCADA or building management systems. This transforms the breaker from a passive device into an active component of a smart grid, enabling predictive maintenance, load profiling, and energy efficiency optimization.

Innovation Point 3: Enhanced Safety and Serviceability with Draw-out Design.​ Available in a draw-out version, the E1.2B lu1250​ can be easily racked between “CONNECT,” “TEST,” and “DISCONNECT” positions. This allows for safe functional testing of the protection and control circuits without applying main power, and enables swift removal for maintenance or replacement without disturbing the main busbar connections, drastically reducing downtime during servicing.

Application Cases and Industry Value:

Case Study: Reliability Upgrade for a Pharmaceutical Manufacturing Plant

A pharmaceutical plant with continuous batch processes faced costly production interruptions due to non-selective tripping in its 30-year-old main LV switchgear. A minor fault in a water purification pump would cause the main incomer breaker to trip, shutting down the entire cleanroom environment and ruining batches worth hundreds of thousands of dollars.

The solution was a strategic retrofit, replacing the old main breaker with the intelligent ABB SACE Emax 2 E1.2B lu1250. Engineers used its powerful selective coordination​ software to digitally set the time-current curves of the E1.2B​ and all downstream feeders, creating a perfectly coordinated “discrimination ladder.” During commissioning, a simulated short-circuit test validated that only the targeted feeder breaker operated. Six months after installation, a real-phase fault occurred in a motor starter. As designed, only the respective feeder breaker tripped. The main E1.2B​ and the rest of the plant remained online, preventing an estimated 8-hour shutdown. The plant manager stated, “The SACE Emax 2​ didn’t just protect our cables; it protected our production schedule and our bottom line. The communication feature also gives us a clear window into our main power intake, helping us manage demand charges.”

Related Product Combination Solutions:

ABB Emax 2 E2.2 / E3.2 / E4.2 / E6.2:​ Larger frame breakers in the same series for higher current ratings (e.g., 2000A, 3200A, 4000A, 6300A), used upstream of the E1.2B​ for a fully coordinated distribution system.

ABB Tmax XT Circuit Breakers:​ Molded Case Circuit Breakers (MCCBs) for feeder and branch circuit protection downstream of the SACE Emax 2 E1.2B, achieving full discrimination.

ABB ACH Communication Module:​ Adds communication capability (e.g., Modbus TCP/IP) to the E1.2B, enabling integration with energy management systems.

ABB AR Remote Control Unit:​ Allows for the remote opening/closing and resetting of the E1.2B​ breaker from a control room.

ABB ACD Display:​ A graphic display that connects to the trip unit, providing a local interface for advanced measurements, event logging, and parameter settings.

ABB AGS Earthing Switch:​ A safety accessory for the draw-out version, allowing the earthing of the busbars or cables when the breaker is in the disconnected position.

ABB SD-ANK Mounting Kit:​ A pre-assembled cubicle mounting kit that simplifies and speeds up the installation of the E1.2B​ breaker into new or existing switchboards.

Installation, Maintenance, and Full-Cycle Support:

Professional installation by qualified personnel is essential. For the ABB SACE Emax 2 E1.2B, this involves securely mounting the breaker (fixed or draw-out chassis), connecting the main power cables to the upper and lower terminals with the specified torque, and wiring the auxiliary contacts, shunt trip (if used), and communication cables. The initial configuration is performed via the front-panel interface or dedicated software (e.g., ABB Breaker Setup Tool), where all protection settings (L, S, I, G) are input based on the detailed coordination study. The draw-out version simplifies this process, allowing wiring and testing with the breaker in the isolated “TEST” position.

Routine maintenance primarily involves periodic inspection for dust accumulation, checking tightness of external connections during planned shutdowns, and verifying the functionality via the trip unit’s self-test features. The advanced PR trip unit provides comprehensive event logging, recording the last several trips with pre-fault current values, which is invaluable for post-fault analysis. For major maintenance, the draw-out design allows the breaker to be safely disconnected and rolled out for inspection or testing without touching the main busbars.

We provide comprehensive support for the ABB SACE Emax 2 E1.2B lu1250. from initial system design and coordination studies to after-sales technical consultation and spare parts. We supply only genuine, factory-new ABB components, ensuring maximum safety, performance, and system compatibility. Our experts can assist with configuration, integration into your monitoring network, and optimizing your protection settings for unparalleled electrical network reliability.