APC AR8125 Adjustable Shelf 250lbs 16"-24" Deep Black

APC AR8125 3-Phase 50A Rackmount Automatic Transfer Switch

Overview

The APC AR8125 is a 3-phase, 50A rack-mounted automatic transfer switch (ATS) designed for enterprise and data center environments that require continuous power redundancy. IT and facilities engineers deploy this device to ensure uninterrupted operation of critical servers, storage systems, and networking equipment during utility outages or maintenance. The AR8125 automatically switches connected loads between dual power sources, maintaining reliable power delivery to sensitive electronic equipment.

The switch supports 208/220/240V AC three-phase input with a rated current of 50A per phase. Switchover typically occurs in under 8 milliseconds, minimizing the risk of disruption to connected loads. Input and output connections use hardwired terminal blocks, and dry contact outputs allow integration with centralized monitoring or building management systems. Front-panel LED indicators display source selection, load status, and fault conditions, enabling real-time operational monitoring.

The AR8125 fits standard 19-inch racks and occupies 3U of space, making it suitable for IDF racks, branch office cabinets, and small-to-medium data center environments requiring dual-feed redundancy. Its compact rackmount form factor allows installation alongside UPS systems and PDUs without interfering with cabinet density or airflow.

Integration options include dry contact signaling for building management and IT monitoring platforms, enabling coordinated alerts and automated load transfer. The ATS is compatible with APC and third-party PDUs, supporting utility-to-utility or utility-to-generator dual-feed configurations in North American and international three-phase systems.

A typical deployment scenario includes a rack in a remote office or branch data center with dual incoming feeds. The AR8125 automatically transfers the connected load to the secondary source during primary feed interruptions, ensuring continuous operation of servers, storage, and networking equipment.

This device is not suitable for single-phase deployments or applications exceeding 50A per phase. Facilities requiring modular ATS expansion, higher amperage, or full building-level integration should select enterprise-class ATS solutions.

Key Features

• 3-phase 50A rack-mounted automatic transfer switch
• Sub-8 ms rapid source switchover for critical IT loads
• LED indicators and dry contacts for real-time monitoring
• Compatible with dual-feed UPS and PDU systems
• Standard 19-inch 3U rackmount form factor

Technical Specifications