DS4820R10 | Replace DS4820R09 Direct

Description

Product Introduction

If the Mark V rack is the body, the DS4820R10 is the heart—pumping 20 amps of 24V DC power to every module in the system. This high-capacity power supply sits in the dedicated PSU slot at the far end of the rack, converting incoming AC into clean, regulated DC. It’s sized for fully populated racks with CPUs, communications modules, and I/O boards.

Compared to the DS4820R09, the R10 is a major upgrade: output current increased from 15A to 20A, and the supply now includes active power factor correction (PFC) to reduce harmonic distortion and improve efficiency. The hold-up time also improved from 15ms to 25ms, giving your UPS a better chance to transfer during a power dip. The terminal and form factor are identical—direct drop-in, but you’ll need to verify your rack’s total load before swapping. No firmware changes required.

Key Technical Specifications

Compatible Replacement Models

Frequently Asked Questions (FAQ)

Q: What’s the difference between the R10 and the R09?
The R10 has a 20A output (vs. 15A) and active power factor correction (PFC). The hold-up time is 25ms vs. 15ms. The R10 also has a slightly better efficiency (90% vs. 88%) and a larger input filter for better noise immunity. If you’re building a new rack or have a high-density configuration, the R10 is the way to go. If you have a lightly loaded rack, the R09 is fine—but the R10 is backward-compatible.

Q: Can I run two R10 supplies in parallel for redundancy?
Yes—the R10 has internal OR-ing diodes, so you can parallel two units. Connect the DC outputs together (+24V to +24V, 0V to 0V) and feed the AC inputs from separate breakers or UPS feeds. Each supply will share the load roughly equally (within 5%). If one fails, the other takes the full load seamlessly. GE recommends each supply be sized for 50% of the total load—so for a rack drawing 15A, use two 10A supplies (or two R10s with one derated). Don’t exceed the R10’s output in redundant mode.

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 R10 has a temperature sensor on the heatsink—if it hits 80°C, it’ll flag a fault but keep running (it shuts down at 85°C). Check the fan—it’s user-replaceable (92mm x 25mm, 12V DC). If the fan is stalled, the supply will derate and eventually shut down.

Q: What’s the hold-up time, and why does it matter?
Hold-up time is how long the supply maintains 24V output after AC input is lost. The R10’s 25ms is enough for most UPS transfers (typical transfer time is 10-15ms). If your UPS is slow (some older units transfer in 30ms), you’ll see a momentary drop on the 24V bus—which can reset the CPU. If you’re on a weak grid or a generator, consider adding a 24V battery-backed DC bus or upgrading the UPS.

Q: The 24V output measures 23.5V, not 24V. Is the supply failing?
The R10 has a fixed, non-adjustable output. If it’s below 24.0V, it’s likely loaded beyond 20A or the internal reference has drifted. Measure the voltage at the backplane connector (not the output terminals, as there’s a voltage drop across the OR-ing diode). If it’s below 23.8V at no load, the supply may need replacement. At full load, 23.5V is within spec (±2% = 23.5V to 24.5V). Check your load—a fully loaded Mark V rack with 10 I/O modules can draw up to 18A.

Q: The fan is loud and runs continuously. Is that normal?
The R10’s fan is temperature-controlled. At low loads (<100W), it should run at low speed (barely audible). At high loads (>300W), it ramps to full speed—which is noticeable. If it’s running at full speed at idle, the temperature sensor may be faulty or the heatsink is blocked with dust. Blow out the unit with compressed air (hold the fan blade to prevent overspeed). If the fan speed doesn’t change with load, the fan control circuit may be dead—the fan defaults to full speed as a fail-safe.

Q: Can I use the R10 on a 100V AC supply?
Yes—the input is auto-ranging from 100-240VAC. At 100VAC, the input current is higher (about 6A at full load vs. 3A at 240VAC). Make sure your branch breaker is rated for at least 10A. Also, at 100VAC, the hold-up time drops to about 18ms because the input capacitors have less voltage to store energy. If you’re in a 100V region (e.g., Japan), consider using a 120V step-up transformer or a UPS.

Q: The Overload LED is amber. What does that mean?
Amber Overload LED indicates the supply is drawing more than its continuous rating (20A). At loads between 20A and 24A, it’ll light amber and continue running—but the output voltage may droop (down to 22V). If the load exceeds 24A, the supply enters foldback current limiting (output drops to about 12V, and the LED flashes). Check your rack’s total load—a fully populated Mark V rack with 10 I/O modules and a CPU can draw up to 18A, so you should be fine. If you’re above 20A, consider adding a second supply in parallel.

Q: Can I hot-swap the R10 while the rack is powered?
The R10 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 while the other carries the load—but only if the OR-ing diodes are installed (they’re internal to the R10). Verify the DC outputs are connected together before attempting. If you’re unsure, consult GE’s manual GEK-108856.

Q: What’s the expected lifespan of the R10?
The electrolytic capacitors are rated for 10,000 hours at 85°C—about 1.1 years at full load in a hot environment. In a 40°C cabinet, the lifespan extends to about 15-20 years. The fan is the most likely failure point—it’s rated for 50,000 hours at 40°C. Replace the fan every 5 years proactively if the cabinet runs warm. We’ve seen R10s run 15 years with no issues in climate-controlled cabinets.

Q: What’s the lead time for a surplus R10?
We keep 4-6 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. If you need the unit urgently for a critical outage, we can arrange expedited shipping—contact us directly.

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