abb Automatic transfer switch 125 amps with 3 Poles

Why Choose the ABB OTM125F3C21D400C Automatic Transfer Switch?

The ABB OTM125F3C21D400C is a compact and highly reliable automatic transfer switch (ATS) designed for efficient switching between power sources in industrial and commercial electrical systems. As part of the trusted ABB OTM motorised change-over switch range, this switch provides dependable automatic transfer functionality for applications requiring continuous power availability and operational safety.

Engineered for standby generator systems and dual power supply applications, the OTM series combines motorised automation with compact switchboard-friendly construction. ABB transfer switches are widely used by electrical engineers and panel builders for critical installations where reliable source switching and minimal downtime are essential.

With a 125 A current rating, 3-pole switching configuration and a 400 V AC motor operating voltage, the OTM125F3C21D400C is ideal for low-voltage power transfer systems in industrial automation, commercial buildings and backup power installations. Its motorised operating mechanism enables smooth automatic operation while supporting manual emergency control when required.

Key Advantages

• Compact automatic transfer switch for critical power continuity.
• 125 A operational current rating for low-voltage power systems.
• 3-pole switching configuration for phase conductor transfer.
• Reliable motorised automatic transfer operation.
• Suitable for generator backup and dual-source applications.
• Compact design simplifies installation in electrical panels.

Key Features

• ABB OTM automatic transfer switch series.
• 125 A rated operational current.
• 3-pole automatic change-over switching.
• 400 V AC motor operating mechanism.
• Automatic and manual operating functionality.
• Suitable for mains-to-generator switching systems.
• Compact base mounted construction.
• High mechanical and electrical endurance.

Technical Specifications

• Manufacturer: ABB
• Series: OTM Automatic Transfer Switches
• Model: OTM125F3C21D400C
• Product type: Automatic transfer switch
• Rated operational current: 125 A
• Number of poles: 3P
• Motor operating voltage: 380–415 V AC
• Rated operational voltage: up to 690 V AC
• Frequency: 50 / 60 Hz
• Protection rating: IP20 front protection
• Mounting type: Base mounting
• Operation type: Motorised automatic operation
• Transition type: Open transition
• Short-circuit withstand: High short-time withstand capability
• Dimensions (H × W × D): approx. 230 × 210 × 145 mm
• Weight: approx. 4.8 kg

Reliable Automatic Source Switching for Electrical Systems

Automatic transfer switches such as the ABB OTM125F3C21D400C automatically switch electrical loads between available power sources during supply interruptions or generator startup conditions. This ensures operational continuity while protecting critical systems against unexpected power loss.

ABB OTM transfer switches are designed for long-term reliability and are widely used in commercial buildings, industrial facilities and generator control systems. Their motorised operation and compact design make them ideal for modern low-voltage switchboards and automation installations.

Typical Applications

• Automatic mains and standby generator systems.
• Industrial power distribution panels.
• Commercial buildings and facilities management.
• Backup power and emergency supply systems.
• Electrical switchboards and automation systems.
• Low-voltage power transfer applications.

Trusted by Electrical Engineers Worldwide

ABB OTM automatic transfer switches are trusted worldwide for dependable source transfer operation, compact design and reliable performance in critical power applications.