1SDA073521R1 ABB E1.2B/MS 1250 4p WMP Switch Disconnector

Why Choose the ABB E1.2B/MS 1250 4p WMP Switch Disconnector?

The ABB E1.2B/MS 1250 4p WMP, order code 1SDA073521R1, is a four-pole withdrawable air switch disconnector from the ABB SACE Emax 2 range, designed for dependable switching and electrical isolation in low-voltage power distribution systems. Built on the compact E1.2 frame, this /MS configuration provides a 1250 A rated uninterrupted current for industrial, commercial and infrastructure switchboards.

The E1.2B/MS combines its continuous-current capability with a rated short-time withstand current of 42 kA for 1 s and 24 kA for 3 s. It is designed as a switch disconnector rather than an automatically tripping circuit breaker, allowing suitably coordinated protective equipment elsewhere in the installation to provide overload and short-circuit protection.

This model is supplied as the withdrawable moving part (WMP) with four poles and a neutral pole rated at 100% of Iu. It supports a rated operational voltage of 690 V AC, a rated insulation voltage of 1000 V AC and utilisation category AC-23A, making it a robust solution for serviceable low-voltage switchboard applications.

Key Advantages

• 1250 A rated uninterrupted current for substantial low-voltage distribution loads.
• 42 kA short-time withstand current for 1 s for demanding switchboard applications.
• 24 kA short-time withstand current for 3 s provides additional verified withstand performance.
• Four-pole construction with 100% neutral rating for simultaneous phase and neutral switching.
• Withdrawable moving-part design supports inspection, servicing and switchboard maintenance.
• 690 V AC operational voltage and 1000 V AC insulation voltage.
• AC-23A utilisation category for demanding switching duties.
• Complies with IEC 60947-3 switch-disconnector isolation requirements.

Key Features

• ABB SACE Emax 2 E1.2B/MS air switch disconnector.
• 1250 A rated uninterrupted current (Iu).
• Four-pole configuration.
• Neutral pole current: 100% of Iu.
• 42 kA rated short-time withstand current (Icw) for 1 s.
• 24 kA rated short-time withstand current (Icw) for 3 s.
• 690 V AC rated operational voltage (Ue).
• 1000 V AC rated insulation voltage (Ui).
• 12 kV rated impulse withstand voltage (Uimp).
• 50/60 Hz operating frequency.
• AC-23A utilisation category.
• Withdrawable moving part (WMP) configuration.
• 244 W power loss.

Reliable Withdrawable Isolation for Low-Voltage Distribution

ABB SACE Emax 2 /MS devices are switch disconnectors designed to satisfy the isolation requirements of IEC 60947-3. They are derived from the Emax 2 circuit-breaker platform and provide the switching and isolation function without the automatic protection trip unit used by the corresponding circuit breakers. When open, the switch disconnector provides the isolating separation required for downstream equipment.

The withdrawable construction allows the E1.2B/MS moving part to be separated from its corresponding fixed switchboard section, supporting maintenance and equipment servicing. Combined with its 1250 A current rating, four-pole configuration and 42 kA 1-second short-time withstand capability, the 1SDA073521R1 is well suited to distribution systems requiring dependable isolation and a serviceable switchgear architecture.

Typical Applications

• Low-voltage main distribution switchboards.
• Industrial power distribution systems.
• Commercial and infrastructure electrical distribution.
• Incoming and outgoing switching and isolation duties.
• Transformer secondary distribution systems.
• Generator and standby power installations.
• Manufacturing and process plant switchgear.
• Withdrawable switchboard assemblies requiring serviceable four-pole isolation.