ABB SACE Emax 2 Low voltage air circuit breakers

Here is a comprehensive overview of the ABB SACE Emax 2 low voltage air circuit-breaker.

The SACE Emax 2 is the evolution of ABB's highly successful Emax line, representing a state-of-the-art solution for low voltage power distribution and protection. It's designed for high-performance applications in commercial buildings, industrial plants, and infrastructure projects.

Key Features and Highlights

Compact and Modular Design: The E2 is significantly more compact than its predecessors, allowing for space savings in switchboards. Its modular design allows for easy customization and adaptation to various applications.

Advanced Trip Unit (PR122/P, PR123/P): The heart of the Emax 2 is its intelligent trip unit. It provides:

Protection Functions: Comprehensive protection against overcurrents (L), short-circuits (I), earth faults (G), and neutral protection (N).

Power Quality Measurement: Monitors key electrical parameters like voltage, current, power (kW, kVAR, kVA), power factor, frequency, and energy (kWh).

Communication Ready: Built-in communication ports (e.g., Ethernet) for easy integration into monitoring and control systems like ABB Ability™.

High Breaking Capacity: Offers extremely high short-circuit breaking capacities (up to Icu=Ics=200kA at 415V AC according to IEC 60947-2), ensuring safety and reliability in demanding networks.

Selectivity and Cascading: Excellent selectivity (discrimination) with downstream breakers minimizes downtime during a fault by isolating only the affected circuit. Its cascading capabilities allow the use of less robust downstream breakers, optimizing cost.

Versatility: Available in four frame sizes (E2.2, E2.4, E2.6, E2.8) covering a current range from 800A to 6300A. It can be used as a:

Circuit Breaker

Isolator (with visible contacts)

Contactor (for remote switching, E2.2 & E2.4 only)

Main Components

Component Description

Frame The main insulating housing, available in four sizes (E2.2 to E2.8).

Operating Mechanism The spring-charging mechanism for opening and closing. Can be manual or motorized.

Trip Unit (PR122/P, PR123/P) The "brain" of the breaker. It analyzes current and decides when to trip. The PR123/P offers more advanced features and a larger display.

Poles Available in 3-pole and 4-pole versions.

Terminals Front or rear terminals, with various connection options (e.g., busbar, cable).

Accessories A wide range including auxiliary contacts, shunt trips, under-voltage releases, locking devices, and communication modules.

Common Applications

The SACE Emax 2 is used as a main incoming breaker, a sub-distribution breaker, or for protecting large individual loads.

Main LV Switchboard (MLVS): As the primary breaker from the transformer.

Industrial Plants: Protecting feeders to large motors, transformers, and capacitor banks.

Data Centers: As a main and critical power distribution breaker.

Commercial Buildings: In the main electrical room for the building's power supply.

Infrastructure: In hospitals, airports, and railway systems.

Key Technical Data (Summary)

Parameter Range / Value

Rated Current (Iu) 800 A to 6300 A

Rated Voltage (Ue) Up to 690 V AC, 1000 V AC (special versions)

Rated Frequency 50/60 Hz

Breaking Capacity (Icu/Ics) Up to 200 kA at 415V AC

Standards IEC 60947-2, UL 489, CSA C22.2

Poles 3 and 4

Trip Units PR122/P, PR123/P

Comparison: PR122/P vs. PR123/P Trip Units

Feature PR122/P PR123/P

Display Graphical High-resolution Graphical

Protection Standard (L, I, G, N) Advanced (adds Pre-Alarm, Thermal Memory)

Measurement Basic electrical parameters Comprehensive power quality & energy

Logging Event log (last 10 faults) Extended event log & load profile

Communication Standard (e.g., Ethernet) Standard (e.g., Ethernet)

Why Choose the SACE Emax 2?

Reliability: Robust design for long service life and dependable operation under fault conditions.

Safety: Meets and exceeds international standards, with clear indicators and multiple safety interlocks.

Efficiency: Power quality monitoring helps identify areas for energy savings and improve system efficiency.

Connectivity: Seamless integration into Building Management Systems (BMS) and Industrial IoT platforms for smart grid readiness.

Ease of Use: Intuitive user interface on the trip unit for configuration and reading measurements.

In summary, the ABB SACE Emax 2 is a versatile, intelligent, and powerful air circuit-breaker designed for modern low voltage electrical systems where safety, reliability, and data-driven insights are paramount. It is a cornerstone of ABB's digital offering for electrical distribution.

For specific technical drawings, detailed dimensional data, or configuration files, it is always best to consult the official ABB SACE Emax 2 catalog or use their online tools like the ABB Circuit Breaker Configuration (CBC) suite.