1SDA055745R1 ABB E1N 1250 PR121/P-LSI 1250A 3P Withdrawable Air Circuit Breaker

Why Choose the ABB E1N 1250 PR121/P-LSI 1250A 3P Withdrawable Air Circuit Breaker?

The ABB E1N 1250 PR121/P-LSI, order code 1SDA055745R1, is a high-performance three-pole withdrawable air circuit breaker designed for protection and switching in demanding low-voltage electrical distribution systems. Part of the ABB SACE Emax E1N series, it combines a 1250 A rated current with the electronic PR121/P-LSI overcurrent release for dependable overload and short-circuit protection.

The withdrawable design makes the E1N 1250 particularly suitable for switchboards where maintainability and continuity of service are important. Its draw-out architecture allows the breaker moving part to be isolated and removed from the associated fixed part for inspection, servicing or replacement, reducing the need to disturb permanent power connections within the switchboard.

The E1N performance level provides a 50 kA short-circuit breaking capacity for demanding power distribution applications. The PR121/P-LSI electronic release incorporates long-time, short-time and instantaneous protection functions, providing coordinated protection against overloads and short circuits in industrial, commercial and infrastructure power networks.

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 applications.
• Three-pole configuration for three-phase electrical systems.
• PR121/P-LSI electronic protection release provides long-time, short-time and instantaneous protection.
• 50 kA E1N short-circuit breaking performance for demanding distribution networks.
• Withdrawable / draw-out construction facilitates inspection, maintenance and replacement.
• Supports protection coordination and selective fault isolation within low-voltage distribution systems.

Key Features

• ABB SACE Emax E1N series.
• 1250 A rated current.
• 3-pole air circuit breaker.
• PR121/P-LSI electronic overcurrent release.
• Long-time (L), short-time (S) and instantaneous (I) protection functions.
• 50 kA E1N breaking-capacity class.
• Withdrawable / draw-out configuration.
• Suitable for main incomer, feeder and distribution protection duties.
• Designed for integration with the appropriate ABB Emax withdrawable fixed part.
• Service-friendly architecture for critical low-voltage switchgear.

Selective Protection for Low-Voltage Distribution Systems

Air circuit breakers such as the ABB E1N 1250 provide switching and automatic protection for high-current low-voltage circuits. The electronic release monitors current conditions and trips the breaker when configured protection thresholds are exceeded, helping protect cables, switchgear and connected equipment against damaging overload and short-circuit currents.

The PR121/P-LSI release adds short-time protection to the long-time and instantaneous functions, allowing greater flexibility when coordinating upstream and downstream protective devices. Combined with the withdrawable E1N platform, this makes the 1SDA055745R1 well suited to installations where selective protection, high fault interruption capability and straightforward maintenance are important.

Typical Applications

• Low-voltage main distribution switchboards.
• Industrial power distribution systems.
• Main incomer and feeder circuit protection.
• Manufacturing and process plants.
• Commercial and infrastructure electrical installations.
• Generator and transformer distribution systems.
• Withdrawable switchgear requiring selective high-current circuit protection.