APC by Schneider Electric AP4431A Rack Automatic Transfer Switch, 2U, 30A, 208V
Overview
The AP4431A is a 2U horizontal rack-mount Automatic Transfer Switch (ATS) designed to eliminate single-point power failure for rack-mounted equipment operating on 208V three-phase or single-phase circuits. By accepting two independent 30A/208V input feeds — each terminated with an L6-30P plug on an 8-foot (2.44m) factory-attached cord — and presenting a single L6-30R output to your load, the AP4431A lets you connect two separate utility feeds or UPS units and switch between them instantly on primary-source failure. The result: your servers, storage arrays, or network gear keep running through a source transfer event without manual intervention.
With a rated load capacity of 4,992 VA at 208V and 30A maximum current, the APC by Schneider Electric AP4431A covers the power envelope of a densely populated 1U or 2U server, a mid-range storage controller, or a combination of critical rack appliances that must never lose power during a feed switchover. If you are building out a rack PDU and power distribution architecture with full path redundancy, this unit belongs at the top of the bill of materials.
Key Features
- Dual 30A/208V L6-30P Inputs: Two fully independent input feeds connect to separate breaker circuits, separate UPS units, or separate utility panels. If Source A drops, the ATS transfers to Source B — no manual switching, no downtime for the connected load. Both inputs carry the same 30A/208V rating, so either source can carry full load without derating.
- 4,992 VA Load Capacity: At 208V and 30A, the AP4431A supports loads up to 4,992 VA — enough headroom for a power-hungry 1U compute node or a mid-density storage controller. Size your connected equipment at no more than 80% of rated capacity (≈3,994 VA / ≈24A) for continuous operation per standard electrical practice.
- Single L6-30R Output: One NEMA L6-30R receptacle feeds the connected equipment. This keeps the downstream load cabling simple — one cord from the ATS to the device, regardless of how many input sources are active. Suitable for equipment with a single power inlet that you want protected by dual-feed redundancy at the rack level.
- 2U Horizontal Rack Mount: At 432mm wide (standard 19-inch rack width) and 236mm deep, the AP4431A mounts horizontally in any standard EIA-310 rack or Netshelter rack enclosure. The 2U profile is a reasonable tradeoff for a dedicated transfer switch that replaces more complex dual-corded server configurations.
- 8-Foot (2.44m) Factory-Attached Input Cords: Both input cords ship pre-terminated at the correct length for reaching typical overhead or underfloor power whips in a standard rack bay. No field termination required on the input side — plug and commission.
- Wide Operating Temperature Range (-5°C to 45°C): The AP4431A operates across the full ASHRAE Class A2 envelope used by most data center and IDF/MDF environments. At 45°C upper limit, it handles elevated ambient conditions in poorly cooled equipment rooms without derating — a practical consideration for edge deployments and remote sites.
- 0–95% Operating Humidity (Non-Condensing): Broad humidity tolerance means the unit works in environments ranging from bone-dry raised-floor data centers to higher-humidity industrial or warehouse edge locations without requiring additional environmental conditioning for the ATS itself.
- 50–60 Hz Input Frequency Compatibility: Accepts both 50 Hz and 60 Hz supply frequencies, so the same SKU deploys in North American (60 Hz) and international (50 Hz) facilities. Useful for organizations standardizing rack-level power infrastructure across geographies.
Integration & Compatibility
The AP4431A fits into any power redundancy architecture where the connected device has a single power inlet. It is most commonly deployed in front of servers, storage arrays, or network video recorders that lack built-in dual-PSU capability, effectively granting those single-inlet devices the same feed-level redundancy as dual-corded enterprise equipment. Upstream, it connects to any 30A/208V L6-30P-terminated circuit — standard output from most 208V rack PDUs, transfer switches, or UPS bypass outputs. Verify that both upstream source circuits are on separate electrical panels or separate UPS units; connecting both inputs to the same upstream source defeats the redundancy purpose. The unit ships in black finish to match standard Netshelter rack aesthetics.
Frequently Asked Questions
Q: What input plug type does the AP4431A use, and what circuit breaker size does it require?
A: Both inputs use NEMA L6-30P plugs on factory-attached 2.44m (8 ft) cords. Each input requires a dedicated 30A/208V circuit. Per NEC 80% rule, the continuous load on each feed should not exceed 24A for code-compliant installations.
Q: What is the maximum VA load the AP4431A can support?
A: The AP4431A is rated at 4,992 VA at 208V/30A. For continuous operation, size the connected load at no more than 80% of that — approximately 3,994 VA or 19.2A at 208V.
Q: Does the AP4431A support both 50 Hz and 60 Hz power?
A: Yes. The unit accepts 50–60 Hz input frequency, making it suitable for both North American (60 Hz) and international (50 Hz) deployments without any configuration change.
Q: What is the output receptacle type on the AP4431A?
A: The AP4431A provides a single NEMA L6-30R output receptacle. The connected device must have a compatible L6-30P plug or cord set rated for 208V/30A.
Q: How much rack space does the AP4431A occupy?
A: The unit is 2U high and 432mm (standard 19-inch) wide, mounting horizontally in any EIA-310-compliant rack or Netshelter enclosure. Depth is 236mm, which fits comfortably in most 600mm or 1000mm deep rack cabinets.
Q: What is the operating temperature range for the AP4431A?
A: The AP4431A operates from -5°C to 45°C (23°F to 113°F) and can be stored from -25°C to 65°C (-13°F to 149°F). This covers ASHRAE Class A2 data center environments and most edge/industrial equipment rooms.
The AP4431A solves a specific and common gap in rack power design: you have dual upstream sources — two PDUs, two UPS units, or a UPS and a bypass — but the device you need to protect has only a single power inlet. Rather than accepting that limitation, you install this 2U ATS in front of it. The 4,992 VA / 30A ceiling means the AP4431A covers the vast majority of single-inlet servers and storage controllers that would otherwise represent a single point of failure in an otherwise redundant infrastructure stack.
Technical Highlights:
- 4,992 VA / 30A Rated Load: Supports full-density 1U compute or mid-range storage at rated input. The 80% continuous-use ceiling lands at about 3,994 VA — plan your load sizing before commissioning, not after.
- Dual L6-30P Inputs on 2.44m Cords: Factory-terminated cords reach standard overhead power whips in a 42U Netshelter bay without extension. Both inputs rated identically — no asymmetric source derating to manage.
- -5°C to 45°C Operating Range: The 45°C upper limit covers ASHRAE A2 and most edge/telco environments where ambient can spike during cooling failures — the scenario where you most need the ATS to hold steady.
Deployment Considerations:
- Both input circuits must originate from electrically independent sources — separate panels, separate UPS units, or a UPS plus utility bypass. Wiring both L6-30P inputs to the same upstream breaker panel defeats the redundancy the AP4431A is designed to provide.
- The AP4431A provides a single L6-30R output only — this is a one-load device. If your rack has multiple single-inlet devices requiring redundant feeds, you need one ATS per device or a different power architecture (such as a dual-input PDU serving multiple outlets).
The AP4431A is the right fit for colocation customers or enterprise IDF/MDF closets where the facility provides two independent 208V/30A feeds per rack bay and the target device — a firewall appliance, a NVR, or a single-PSU server — cannot consume both feeds natively.
