1SDA055642R1 ABB E1B 1250 PR121/P-LSIG 1250 A 4-Pole Air Circuit Breaker

Why Choose the ABB E1B 1250 PR121/P-LSIG Air Circuit Breaker?

The ABB E1B 1250 PR121/P-LSIG, order code 1SDA055642R1, is a high-performance SACE Emax air circuit breaker designed for protection and switching in low-voltage power distribution systems. This four-pole fixed circuit breaker combines a 1,250 A rated current with the PR121/P-LSIG R1250 electronic overcurrent release for long-time overload, short-time short-circuit, instantaneous short-circuit and earth-fault protection.

Part of the proven ABB SACE Emax E1 series, the E1B 1250 is suited to industrial switchboards, commercial power distribution assemblies and infrastructure installations requiring dependable high-current protection. Its LSIG protection functions provide comprehensive coverage against overloads, short circuits and earth faults in demanding low-voltage networks.

This configuration is a four-pole fixed circuit breaker with rear horizontal flat terminals. The E1B performance level provides a rated ultimate short-circuit breaking capacity of 42 kA at 400 V AC, while the four-pole arrangement makes the breaker suitable for three-phase four-wire distribution systems requiring simultaneous switching of phase and neutral conductors.

Key Advantages

• High-capacity 1,250 A SACE Emax air circuit breaker for demanding low-voltage distribution.
• PR121/P-LSIG electronic trip unit provides long-time, short-time, instantaneous and earth-fault protection.
• Four-pole configuration supports three-phase four-wire distribution systems.
• 42 kA ultimate short-circuit breaking capacity at 400 V AC.
• Rear horizontal flat terminals provide a practical interface with switchboard busbar systems.
• Fixed construction provides secure permanent integration into low-voltage switchboards.

Key Features

• ABB SACE Emax E1B series.
• 1,250 A rated uninterrupted current.
• Four-pole configuration.
• Fixed circuit-breaker execution.
• Rear horizontal flat terminals.
• PR121/P-LSIG R1250 electronic overcurrent release.
• Long-time overload protection.
• Short-time short-circuit protection.
• Instantaneous short-circuit protection.
• Integrated earth-fault protection.
• 42 kA Icu at 400 V AC.
• Adjustable overload and short-circuit protection settings.
• Optional motor operating mechanism capability.

Comprehensive LSIG Protection for High-Current Distribution

The ABB SACE Emax E1B provides switching, isolation and electronic overcurrent protection for high-current low-voltage distribution circuits. Its PR121/P-LSIG release combines long-time overload, short-time and instantaneous short-circuit functions with earth-fault protection, helping safeguard cables, busbars, transformers and downstream electrical equipment against a broad range of fault conditions.

The four-pole fixed construction is particularly suitable for three-phase four-wire switchboards where neutral switching is required alongside the phase conductors. Rear horizontal flat terminals facilitate connection to switchboard busbars, while adjustable protection settings allow the breaker to be coordinated with the requirements of the protected distribution circuit.

Typical Applications

• Low-voltage main distribution switchboards.
• Industrial power distribution systems.
• Three-phase four-wire electrical networks.
• Commercial building electrical distribution.
• Infrastructure and utility installations.
• Transformer secondary distribution circuits.
• Generator and standby power distribution systems.