1SDA055857R1 ABB E2N1250 PR121/P-LSI 1250 A 3-Pole Fixed Air Circuit Breaker

Why Choose the ABB 1SDA055857R1 E2N1250 Air Circuit Breaker?

The ABB 1SDA055857R1 is a SACE New Emax E2N1250 air circuit breaker (ACB) designed for dependable switching and protection in demanding low-voltage electrical distribution systems. This three-pole fixed circuit breaker has a rated uninterrupted current of 1250 A and is equipped with the ABB PR121/P-LSI electronic overcurrent release.

The PR121/P-LSI trip unit provides long-time (L), short-time (S) and instantaneous (I) protection. This combination protects against overload and short-circuit conditions while the adjustable short-time function supports selective coordination between upstream and downstream protective devices in industrial and commercial power distribution networks.

The E2N1250 performance level provides a rated ultimate short-circuit breaking capacity of 65 kA at 400 V AC and 55 kA at 690 V AC. With its three-pole fixed construction, rear horizontal terminal arrangement and robust electrical characteristics, the 1SDA055857R1 is well suited to main distribution and high-current feeder applications.

Key Advantages

• Genuine ABB SACE New Emax E2N1250 air circuit breaker.
• 1250 A rated uninterrupted current for high-current low-voltage distribution.
• Three-pole fixed configuration for three-phase electrical systems.
• PR121/P-LSI electronic overcurrent release.
• Provides long-time, short-time and instantaneous protection.
• 65 kA Icu at 400 V AC for demanding prospective fault-current conditions.
• Short-time protection supports improved selectivity and coordination within distribution networks.

Key Features

• ABB SACE New Emax E2N1250 series.
• 1250 A rated uninterrupted current.
• 690 V AC rated operational voltage.
• Three-pole fixed construction.
• PR121/P-LSI electronic trip unit.
• Long-time overload protection.
• Short-time delayed short-circuit protection.
• Instantaneous short-circuit protection.
• 65 kA Icu and Ics at 400 V AC.
• 55 kA Icu and Ics at 690 V AC.
• 55 kA short-time withstand current for 1 s.
• 1000 V rated insulation voltage.
• 12 kV rated impulse withstand voltage.
• Rear horizontal terminal arrangement for fixed switchgear installation.

Selective High-Performance Protection for Power Distribution

Air circuit breakers such as the ABB SACE New Emax E2N1250 provide switching, isolation and overcurrent protection for high-current low-voltage distribution circuits. The E2N performance level offers substantial short-circuit interruption capability, including 65 kA at 400 V AC, making the breaker suitable for installations with demanding prospective fault-current levels.

The PR121/P-LSI release combines long-time overload, short-time delayed short-circuit and instantaneous short-circuit protection. The short-time function is particularly useful for selective coordination, allowing appropriately configured downstream protective devices an opportunity to clear faults before the upstream E2N1250 operates.

Typical Applications

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