1SDA056369R1 ABB E3H1250PR121/P-LSI 1250 A 3-Pole Air Circuit Breaker

Why Choose the ABB E3H1250PR121/P-LSI Air Circuit Breaker?

The ABB E3H1250PR121/P-LSI is a high-performance three-pole air circuit breaker (ACB) designed for reliable protection, switching and isolation in low-voltage electrical distribution systems. As part of the proven ABB SACE Emax E3H series, this fixed circuit breaker combines a 1250 A rated uninterrupted current with the PR121/P-LSI electronic overcurrent release for dependable protection in demanding industrial and commercial installations.

The PR121/P-LSI R1250 electronic trip unit provides long-time overload, short-time delayed short-circuit and instantaneous short-circuit protection. These adjustable LSI protection functions enable effective coordination with other protective devices while helping safeguard conductors, switchgear and connected equipment against sustained overloads and severe fault conditions.

The ABB 1SDA056369R1 is supplied as a three-pole fixed E3H 1250 circuit breaker with rear horizontal terminals. With a rated operational voltage of 690 V AC, high short-circuit interruption capability and four auxiliary change-over contacts, it is well suited to main switchboards, industrial distribution systems and other high-current low-voltage installations.

Key Advantages

• High-performance ABB SACE Emax air circuit breaker for low-voltage power distribution.
• 1250 A rated uninterrupted current for high-current electrical systems.
• Three-pole configuration for three-phase distribution applications.
• PR121/P-LSI electronic trip unit provides long-time, short-time and instantaneous protection.
• 100 kA ultimate breaking capacity at 400 V AC for demanding fault-current conditions.
• Fixed-mounted construction for permanent switchboard installations.
• Rear horizontal terminals support practical integration with switchboard busbar systems.

Key Features

• ABB SACE Emax E3H series.
• 1250 A rated uninterrupted current.
• Three-pole circuit breaker configuration.
• PR121/P-LSI R1250 electronic overcurrent release.
• LSI protection functions: long-time, short-time and instantaneous.
• 690 V AC rated operational voltage.
• 100 kA Icu at 400–500 V AC.
• 85 kA Icu at 660–690 V AC.
• Fixed version with rear horizontal terminals.
• Four auxiliary change-over contacts with open/closed circuit-breaker position indication.

Reliable Protection for Low-Voltage Power Distribution

Air circuit breakers such as the ABB SACE Emax E3H protect electrical distribution systems against overload and short-circuit conditions while providing dependable switching and isolation. Their high interrupting capability makes them particularly suitable for main distribution points, industrial switchboards and other installations where prospective fault currents can be substantial.

The PR121/P-LSI electronic release provides adjustable protection characteristics for effective coordination within the distribution system. Long-time protection responds to sustained overloads, short-time protection supports selective fault clearing, and instantaneous protection provides rapid interruption of severe short circuits.

Typical Applications

• Main low-voltage distribution switchboards.
• Industrial power distribution systems.
• Commercial and infrastructure electrical installations.
• Manufacturing plants and process facilities.
• Power distribution centres and electrical substations.
• Generator and transformer distribution systems.
• High-current switchgear and control assemblies.