Delta DPS-280AB-4A — 280W ATX Server PSU, PS/2 Form Factor

DELTA ELECTRONICS · DPS-280AB-4A · 280W ATX PSU · IN STOCK

The Delta DPS-280AB-4A is a 280-watt, 80 PLUS-rated switching power supply built by Delta Electronics (Taiwan) in the PS/2 (deep) form factor. Designed for 1U and 2U rack servers, network appliances, edge gateways and industrial control cabinets that host a controller backplane, it accepts a wide 90–264 VAC auto-ranging input and delivers the +3.3 V / +5 V / +12 V / −12 V / +5 Vsb rails that ATX and EPS12V motherboards expect. KOEED keeps DPS-280AB-4A on the shelf for integrator and field-replacement use — a drop-in retrofit PSU for legacy 1U IPC builds that share a chassis with Siemens SIMATIC, Mitsubishi MELSEC and Omron SYSMAC I/O racks. Send your BOM to Moritta@KOEED.COM and we will get back with availability and price within 24 hours.

Key Technical Specifications & Overview

Application Scenarios & Where It Fits

The DPS-280AB-4A is a generic-purpose 280 W ATX/EPS12V supply, not a brand-locked spare. That makes it a workhorse retrofit in any 1U / 2U chassis that needs stable 12 V for a CPU board, DRAM and a few peripheral cards. At KOEED we most often ship it into the following build patterns:

• 1U industrial servers — fan-cooled compute nodes that aggregate Allen-Bradley ControlLogix and Siemens ET 200 field data and forward it to a SCADA or MES layer.
• Network appliances and firewalls — where the chassis already routes +12 V to a CPU board with embedded KEYENCE vision or barcode trigger I/O.
• Edge gateways and IoT concentrators — DIN-rail or wall-mount boxes that bridge Modbus TCP / EtherNet/IP to MQTT / OPC UA, sitting next to Schneider Modicon and Omron CP1 / CJ2 PLCs.
• Industrial PCs (IPC) in control cabinets — paired with a Panasonic FP or Mitsubishi MELSEC-Q backplane for HMI / data-logging duty.
• CNC retrofit racks — replacement supply for Fanuc 0i / 30i and Yaskawa Σ-7 controller enclosures where the original PSU is EOL and a form-fit drop-in is required.
• Test & measurement racks — bench-top 19-inch racks powering data-acquisition front ends, including KEYENCE laser sensors and vision heads that need clean +12 V / +5 V rails.

If you are unsure whether DPS-280AB-4A is the right Delta SKU for your chassis, send the existing PSU label photo to our AI Diagnostic Tool or attach it to an email to Moritta@KOEED.COM and we will cross-check the pin-out, fan curve and dimensions before you commit.

Integration & Wiring Notes

DPS-280AB-4A follows the ATX12V 2.x signal standard. The PS_ON# signal (green wire, pin 16 on the 24-pin connector) is pulled to +5 Vsb through the motherboard; shorting PS_ON# to ground (any COM pin) turns the supply on. PWR_OK (pin 8, gray wire) rises to +5 V typically 100–500 ms after the rails are stable. Always design a soft-start delay into any custom backplane, and never hot-plug the 24-pin connector under load — the inrush on the bulk +12 V capacitors can exceed 30 A.

• Main board power: 24-pin ATX12V, keying matches the EPS12V socket on most server motherboards used in Allen-Bradley and Siemens industrial PC builds.
• CPU rail: 8-pin (or 4+4 pin) EPS12V for the processor VRM — required for any modern x86 SBC. Do not daisy-chain the 4-pin to the 8-pin socket.
• Peripherals: the Delta DPS-280AB-4A typically ships with a 6-pin PCIe lead (15 W low-power GPU / NVMe riser) plus a mix of SATA and 4-pin Molex — sufficient for a slimline SBC and one storage device.
• Chassis grounding: bond the PSU chassis to the rack earth bar with a 6 mm² (10 AWG) green/yellow pigtail. The IEC C14 inlet's PE pin is bonded internally; do not rely on the front-panel mounting screws alone.
• Remote on/off logic: if you are driving PS_ON# from a PLC output (for example a Omron CP1H or Mitsubishi FX transistor output), use a small relay or open-collector buffer; do not back-feed 24 V into PS_ON#.
• Cooling airflow: the internal fan pulls air front-to-back. Keep at least 30 mm clearance at the rear exhaust, and never block the front intake with cable bundles.

For legacy Fanuc or Schneider chassis that expect non-standard pin-outs, KOEED can supply a wiring-harness adapter; list the original PSU model on the BOM and we will quote the harness alongside DPS-280AB-4A.

Installation & Commissioning Tips

1. Pre-power inspection. Confirm the AC mains range matches the label (100–120 V or 200–240 V jumper / auto). Verify the IEC C13 cord is rated for the branch-circuit amperage, and the rack PDU outlet is correctly bonded.
2. Mechanical fit. The PS/2 (deep) footprint is 150 × 86 × ~140 mm (W × H × D). Confirm your chassis cut-out matches before mounting screws — a misaligned standoff can warp the PSU housing and short the +12 V rail to chassis.
3. First power-up. With the motherboard removed (or with all peripheral connectors unplugged), short PS_ON# to COM. The fan should spin within one second, and all rails should read within ±5 % tolerance. Use a calibrated DMM on the 24-pin +5 Vsb (pin 9, purple) and +3.3 V (pin 1, orange) sense points.
4. Load test. Apply a dummy 12 V load (a 50 W halogen or electronic load bank) and verify that the fan ramps, the PWR_OK signal asserts, and there is no audible coil whine. A noisy DPS-280AB-4A at light load is often a sign of dried-out bulk capacitors — replace before commissioning the rack.
5. Thermal soak. Run the rack at 100 % CPU + storage load for 60 minutes. The inlet-to-exhaust delta should stay under 12 °C. If it climbs above 18 °C, check the internal fan — Delta OEM fans are field-replaceable on this form factor.
6. Documentation. Log the PSU serial number, lot code and AC mains voltage on the rack commissioning sheet. When you eventually need an AI diagnostic session, that record short-circuits the troubleshooting path.

Need a refresher on ATX signal timing or PWR_OK behavior? Our PLC Error Code Database also covers industrial-PC POST / boot fault codes when a PSU swap does not bring the node back.

Procurement, Warranty & Lead Time

KOEED stocks Delta DPS-280AB-4A as a build-of-material (BOM) item for rack-build integrators and field-replacement projects. Pricing is RFQ-driven rather than list — a single 280 W supply by itself commands a different number than a 50-piece rack roll-out, so we do not publish a price tag on the page. Send a part list to Moritta@KOEED.COM and you will get a written quote (availability + lead time + freight options) within 24 business hours. The same address accepts a full rack BOM — mix the DPS-280AB-4A with Allen-Bradley, Siemens, Mitsubishi, Omron, Fanuc, Schneider, Yaskawa, Panasonic and KEYENCE spares in one email and we will quote the lot.