OXA1000U3O3QT ABB TruONE 1250A 4-Pole Automatic Transfer Switch

Why Choose the ABB TruONE OXA1000U3O3QT Automatic Transfer Switch?

The ABB TruONE OXA1000U3O3QT is a purpose-built 1250 A IEC / 1000 A UL automatic transfer switch for dependable source transfer in critical power distribution systems. Supplied under ABB order code 1SCA153542R1001, it combines the transfer switching mechanism and controller within a single integrated TruONE ATS assembly.

This model has a 4-pole configuration with overlapping neutral and uses open-transition I-II operation. The overlapping-neutral arrangement maintains the neutral connection during the transfer sequence, making the unit suitable for 4-pole systems where neutral continuity during source changeover is required.

The OXA1000U3O3QT features ABB's Level 3 controller with LCD interface and is designed for a 200–480 V AC voltage range. Its top-entry configuration places Source 1 and Source 2 connections at the top and the load connections at the bottom, providing a practical arrangement for switchboards designed around top-fed incoming supplies.

Key Advantages

• 1250 A IEC / 1000 A UL TruONE automatic transfer switch.
• Integrated ATS and controller architecture reduces external wiring and connection points.
• 4-pole overlapping-neutral configuration maintains neutral continuity during transfer.
• Open-transition I-II operation for controlled source transfer.
• Level 3 LCD controller provides advanced monitoring and transfer-control functions.
• Top-entry configuration with Source 1 and Source 2 at the top and load connections at the bottom.
• Wide 200–480 V AC operating voltage range.
• Designed and tested for critical standby and alternative-source power systems.

Key Features

• ABB TruONE ATS integrated automatic transfer switch.
• IEC rated current: 1250 A.
• UL rated current: 1000 A.
• 4-pole configuration.
• Overlapping neutral.
• Open-transition I-II operation.
• Level 3 controller with LCD user interface.
• 200–480 V AC voltage range.
• Top entry: Source 1 and Source 2 connections at top, load connections at bottom.
• Manual operating handle included.
• Detachable HMI arrangement.
• 2 m HMI connection cable included.
• Load-side phase barriers included for this frame size.

Integrated Automatic Power Transfer with Overlapping Neutral

ABB TruONE integrates the automatic transfer switch and controller into one purpose-built assembly, reducing the wiring and separate components associated with conventional ATS installations. The OXA1000U3O3QT automatically manages transfer between two power sources using open-transition I-II operation while providing local monitoring and control through its Level 3 LCD interface.

The overlapping-neutral arrangement is particularly useful in 4-pole installations because the neutral connection is maintained during the source-transfer sequence. Combined with the top-entry connection layout, high-current capability and integrated TruONE architecture, this configuration is well suited to substantial standby and critical-power switchboards.

Typical Applications

• Mains-to-generator automatic transfer systems.
• Critical industrial power distribution.
• Data centres and communications infrastructure.
• Commercial building standby power systems.
• Healthcare and essential-services electrical systems.
• Large generator and alternative-source installations.
• 4-pole systems requiring overlapping-neutral transfer.
• Switchboards requiring top-entry source connections and bottom load connections.