ABB OTM125F4C21D400C automatic transfer switch with 125 A rating, 4-pole switching configuration and 380–415 V AC motor operation for industrial and commercial standby power systems.
£2,148.47
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.
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.
| Current | 125 A |
|---|---|
| Phase | Three Phase |
| IP Rating | IP20 |
| Series | OTM Compact ATS |
| 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 |
| HS Code | 85365080 |
| Country of Manufacture | China |
This automatic transfer switch is used to automatically transfer electrical loads between mains and backup power supplies such as generators.
The switch supports a rated operational current of 125 A for industrial and commercial low-voltage systems.
The motor operated mechanism requires a 380–415 V AC supply.
Yes. The 4-pole configuration allows simultaneous switching of all conductors including the neutral connection.
The unit is commonly installed in switchboards, generator control panels and commercial or industrial power distribution systems.
ABB OTM Compact ATS transfer switches are trusted worldwide for reliable automatic source transfer, compact construction and dependable performance in critical power applications.
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LED Controls is a specialist distributor of factory automation and industrial controls, supplying OEMs, machine builders, panel builders and end users throughout the UK and worldwide. As a trusted UK distributor for many of the world’s leading automation manufacturers, we provide industrial control products, technical expertise and bespoke automation solutions backed by outstanding customer service.
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...
2025 has been a big year for LED Controls, and our blog has expanded accordingly. We've covered a wide range of topics across industrial control and factory automation this year. From core technology explainers and new product releases to panel building best practice...