abb Automatic transfer switch 125 amps with 4 Poles

Why Choose the ABB OTM125F4CB21D400C Automatic Transfer Switch?

The ABB OTM125F4CB21D400C is a compact and dependable automatic transfer switch (ATS) designed for reliable source switching in industrial, commercial and standby power applications. As part of the advanced ABB OTM Compact ATS series, this motor operated change-over switch automatically transfers electrical loads between mains and backup power supplies to help maintain continuous operation of critical systems.

Designed for modern low-voltage power distribution systems, the OTM Compact ATS range combines robust switching capability with compact dimensions and simplified installation. ABB transfer switches are widely trusted by panel builders, electrical contractors and industrial engineers for applications requiring dependable power continuity and efficient automatic source transfer.

With a 125 A operational current rating, 4-pole switching configuration and a 380–415 V AC motor operating voltage, the OTM125F4CB21D400C is ideal for mains-to-generator transfer systems, industrial switchboards and commercial backup power installations. Its self-supplied controller with adjustable operating parameters provides flexible and reliable automatic operation.

Key Advantages

• Compact automatic transfer switch for standby power applications.
• 125 A operational current rating for low-voltage systems.
• 4-pole switching design including neutral switching.
• Reliable motor operated automatic transfer functionality.
• Adjustable operating parameters for flexible system integration.
• Compact footprint simplifies switchboard installation.

Key Features

• ABB OTM Compact ATS series.
• 125 A rated operational current.
• 4-pole automatic change-over switching.
• 380–415 V AC motor operational voltage.
• Motor operated open transition type 1-0-2 switching.
• Self-supplied controller with adjustable operating parameters.
• Base mounting or DIN rail mounting capability.
• Compact enclosed construction for switchboards and control panels.

Technical Specifications

• Manufacturer: ABB
• Series: OTM Compact ATS
• Model: OTM125F4CB21D400C
• Product type: Automatic transfer switch
• Rated operational current: 125 A
• Number of poles: 4P
• Controller type: 21D
• Motor operational voltage: 380–415 V AC
• Rated insulation voltage (Ui): 800 V
• Rated impulse withstand voltage (Uimp): 8 kV
• Rated operational voltage: 380–415 V AC
• Frequency: 50 / 60 Hz
• Protection rating: Front IP20
• Mounting type: Base mounting or DIN rail mounting
• Transition type: Open transition
• Terminal position: Supplies on bottom, load on top
• Fourth pole type: Switched simultaneous function
• Short-time withstand current: 2.5 kA for 1 second
• Dimensions (H × W × D): approx. 103 × 286 × 131 mm
• Weight: approx. 2.11 kg

Reliable Automatic Power Transfer for Critical Systems

Automatic transfer switches such as the ABB OTM125F4CB21D400C continuously monitor power supply availability and automatically transfer connected loads between power sources during supply interruptions. This helps maintain operational continuity while protecting essential systems and reducing downtime.

The ABB OTM Compact ATS range is widely used in generator systems, industrial automation and low-voltage power distribution applications. Its motor operated mechanism and compact design make it ideal for installations where reliable source transfer and efficient panel integration are essential.

Typical Applications

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

Trusted by Electrical Engineers Worldwide

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