531X111PSHACG2 | Replace 531X111PSHACG1

Description

Product Introduction

Racks don’t get more demanding than this. The 531X111PSHACG2 is GE’s latest 500W power supply for the Mark V system, designed to handle the heaviest backplane loads while running cooler and quieter than its predecessor. It’s the power plant for fully populated racks with multiple CPUs, communications cards, and high-current output boards.

Compared to the 531X111PSHACG1, the “G2” revision represents a meaningful hardware refresh: the fan assembly is now modular (user-replaceable without opening the main enclosure), the heatsink was enlarged by 15%, and the efficiency was bumped to 92% at full load. The hold-up time was extended from 35ms to 40ms—a 14% improvement. The terminal assignment is identical—direct drop-in. No firmware changes required.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

Q: What’s the main improvement in the G2 over the G1?
The G2 has a user-replaceable fan module—you don’t need to open the power supply enclosure or send the unit to a repair shop when the fan fails. The efficiency was improved to 92% (vs. 91%), reducing heat generation by about 5W at full load. The hold-up time increased to 40ms (vs. 35ms), giving your UPS more time to transfer. The extended operating temperature range (60°C vs. 55°C) is also a welcome change for plants in hot environments.

Q: How do I replace the fan on the G2?
The fan is a modular assembly accessible from the rear panel. Remove the two retaining screws, pull the fan module straight out, disconnect the 4-pin connector, and slide in the new fan. No soldering, no tools beyond a screwdriver. We recommend replacing the fan every 5-7 years, or when you hear unusual bearing noise. The fan is a standard 92mm x 25mm, 12V DC unit rated at 50 CFM. We can supply replacement fans separately.

Q: The Fault LED is red, but the DC OK LED is green. What’s happening?
Green DC OK means the 24V output is within spec. Red Fault indicates an internal warning—typically overtemperature (fan failure or blocked airflow) or an input voltage out of range (below 85VAC or above 265VAC). The G2’s modular fan assembly makes checking the fan easier—pull it out, spin it by hand to check for bearing roughness, and blow out the heatsink fins. The G2 has a thermal sensor that triggers the fault at 80°C.

Q: The inrush current is 30A peak. Is that a concern for my branch breaker?
30A peak for 2ms is within the tolerance of most 15A C-curve breakers. The G2’s inrush is 5A lower than the G1’s—a welcome improvement. If you have multiple supplies in a panel (e.g., two ACG2s), the combined inrush of 60A may trip a 20A breaker on startup. Use D-curve breakers (which tolerate higher inrush) or sequence the power-up of the supplies by stagerring the AC feeds.

Q: The Overload LED is amber. What does that mean?
Amber Overload LED indicates the supply is drawing more than its continuous rating (20.8A). At loads between 20.8A and 25A, it’ll light amber and continue running—but the output voltage may droop (down to 22V). If the load exceeds 25A, the supply enters foldback current limiting (output drops to about 12V, and the LED flashes). Check your rack’s total load with a clamp meter on the backplane’s 24V line. If you’re consistently seeing amber, consider adding a second supply in parallel.

Q: Can I run two ACG2 supplies in parallel for redundancy?
Yes—the ACG2 has internal OR-ing diodes. Connect the DC outputs together (+24V to +24V, 0V to 0V) and feed the AC inputs from separate breakers. Each supply will share the load roughly equally (within 5%). The blue “Load Share” LED will light when both supplies are contributing. If one fails, the other takes the full load. In a redundant configuration, each supply should be sized for 50% of the load—for a 20.8A total load, two ACG2s would each carry about 10.4A.

Q: Can I hot-swap the ACG2 while the rack is powered?
The board supports hot-swapping when used in a redundant configuration (two supplies in parallel). In a single-supply configuration, pulling the supply will immediately shut down the entire rack—a guaranteed turbine trip. If you have redundant supplies, you can pull one—but only if the OR-ing diodes are present (they’re internal to the ACG2). Verify the DC outputs are connected together before attempting.

Q: What’s the expected lifespan of the ACG2?
The electrolytic capacitors are rated for 12,000 hours at 85°C. In a 40°C cabinet, the lifespan extends to about 18-22 years. The modular fan is rated for 60,000 hours at 40°C (about 6.8 years). The G2’s improved efficiency and larger heatsink help the capacitors run cooler, extending their life vs. the G1.

Q: What’s the lead time for a surplus unit?
We keep 3-5 units in stock. Domestic: 2-3 business days ground, overnight if ordered by 2 PM EST. International: 5-7 days via DHL, with customs potentially adding 1-3 days. This board is not ITAR-controlled, so we can ship to most countries without an export license. We include a GE certificate of origin and commercial invoice with every shipment. Contact us if you need expedited shipping for a critical outage.

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