abb Automatic transfer switch 125 amps with 4 Poles

Why Choose the ABB OTM125F4C21D400C Automatic Transfer Switch?

The ABB OTM125F4C21D400C is a compact and intelligent automatic transfer switch (ATS) engineered for reliable source switching in industrial, commercial and critical backup power systems. As part of the advanced ABB OTM Compact ATS series, this motor operated transfer switch automatically changes between primary and standby power sources to help maintain uninterrupted operation of essential electrical equipment.

Designed for modern low-voltage switchboards and generator systems, the ABB OTM Compact ATS range combines dependable switching performance with compact dimensions and simplified installation. Its integrated controller and motorised mechanism make it ideal for applications where automatic source transfer and operational continuity are critical.

With a 125 A operational current rating, 4-pole switching configuration and a 380–415 V AC motor operating voltage, the OTM125F4C21D400C is suitable for mains-to-generator transfer systems, commercial facilities and industrial power distribution applications. The unit features adjustable operating parameters for flexible system configuration and dependable automatic operation.

Key Advantages

• Compact automatic transfer switch for standby power applications.
• 125 A operational current rating for low-voltage power systems.
• 4-pole switching design including neutral switching.
• Reliable motor operated automatic source transfer.
• Adjustable operating parameters for flexible control integration.
• Compact footprint helps reduce switchboard space requirements.

Key Features

• ABB OTM Compact ATS series.
• 125 A rated operational current.
• 4-pole automatic transfer 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 compatibility.
• Compact enclosed design for switchboards and panels.

Technical Specifications

• Manufacturer: ABB
• Series: OTM Compact ATS
• Model: OTM125F4C21D400C
• 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 type: Screw terminals
• 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 Installations

Automatic transfer switches such as the ABB OTM125F4C21D400C continuously monitor power availability and automatically transfer connected loads between mains and standby power supplies during supply interruptions. This helps minimise downtime and maintain continuity for critical electrical systems and equipment.

The ABB OTM Compact ATS range is widely used by electrical engineers, contractors and panel builders for backup power systems, generator installations and low-voltage distribution networks. Its compact dimensions and dependable motor operated mechanism make it ideal for modern electrical installations requiring reliable source transfer functionality.

Typical Applications

• Automatic mains and generator transfer systems.
• Commercial buildings and facilities management.
• Industrial power distribution systems.
• Critical backup and emergency power installations.
• Electrical switchboards and automation panels.
• 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.