1SDA055740R1 ABB E1N1250 PR122/P-LSI 1250 A 4-Pole Air Circuit Breaker

Why Choose the ABB 1SDA055740R1 E1N1250 Air Circuit Breaker?

The ABB 1SDA055740R1 is a high-performance SACE Emax E1N1250 air circuit breaker (ACB) designed for reliable protection and switching in low-voltage electrical distribution systems. As part of the ABB New Emax series, this four-pole fixed circuit breaker combines a rated current of 1250 A with the advanced PR122/P-LSI electronic overcurrent release.

The PR122/P-LSI trip unit provides long-time (L), short-time (S) and instantaneous (I) protection, allowing the breaker to protect electrical installations against overloads and both delayed and instantaneous short-circuit conditions. Its electronic protection system makes the E1N1250 suitable for demanding industrial and commercial distribution applications where accurate protection coordination is required.

With a rated operational voltage of up to 690 V AC and a rated ultimate short-circuit breaking capacity of 50 kA, the 1SDA055740R1 provides robust performance across high-current distribution systems. This model features a four-pole fixed configuration with rear horizontal flat terminals, making it suitable for installation in switchboards and power distribution assemblies.

Key Advantages

• Heavy-duty ABB SACE Emax air circuit breaker for low-voltage power distribution.
• 1250 A rated current for high-current industrial and commercial installations.
• Four-pole configuration for comprehensive circuit switching and protection.
• Advanced PR122/P-LSI electronic overcurrent release.
• Provides long-time, short-time and instantaneous protection.
• 50 kA ultimate short-circuit breaking capacity across key AC operating voltages.
• Fixed construction with rear horizontal flat terminals for switchboard integration.

Key Features

• ABB SACE New Emax E1N1250 series.
• 1250 A rated uninterrupted current.
• Four-pole fixed version.
• PR122/P-LSI R1250 electronic trip unit.
• Long-time overload, short-time short-circuit and instantaneous short-circuit protection.
• 690 V AC rated operational voltage.
• 50 kA rated ultimate short-circuit breaking capacity (Icu).
• 50 kA rated service short-circuit breaking capacity (Ics).
• 50 kA short-time withstand current for 1 s.
• Rear horizontal flat main circuit terminals.
• Auxiliary contacts and open/closed position indication.
• Optional motor operating mechanism capability.

Reliable Circuit Protection for Power Distribution

Air circuit breakers such as the ABB SACE Emax E1N1250 provide switching, isolation and protection for high-current low-voltage distribution circuits. The electronic protection release continuously monitors electrical conditions and initiates circuit-breaker operation when configured overload or short-circuit thresholds are exceeded.

The PR122/P-LSI release adds short-time protection to the long-time and instantaneous functions, supporting improved protection coordination and selectivity within complex distribution systems. Combined with the breaker’s high short-circuit performance and fixed four-pole construction, this makes the 1SDA055740R1 well suited to demanding switchboard and electrical infrastructure applications.

Typical Applications

• Industrial low-voltage switchboards and distribution panels.
• Main incoming and feeder circuit protection.
• Commercial building electrical distribution systems.
• Manufacturing and process industry power systems.
• Infrastructure and utility distribution equipment.
• High-current machinery and plant electrical installations.