The Dell 3859D (3859D - Dell 410-Watts 100-240V ATX Power Supply for Precision 420) is a Power Supplies & Power Protection component engineered for sustained enterprise-class workloads. Manufactured to OEM specifications and tested for compatibility with Dell PowerEdge R640, R650, R740, R750, R760 and T-series rack and tower servers, this part addresses common procurement scenarios where exact-match replacement, capacity expansion, or new-build deployment is required. Technical specifications include power of 410W, voltage of 240V. Common deployment scenarios include enterprise data-center, server-room, and managed-service-provider environments where matched-OEM-part procurement is required for warranty and compliance continuity. Our procurement team maintains active inventory of the 3859D and verifies condition, firmware revision, and OEM part-number registry alignment for each unit prior to sale. Stocked units ship same-day on in-stock orders placed before 3pm ET. Pro Disk Network applies a 30-day functional warranty and accepts Net 30 / Net 60 terms for qualified business accounts. Free US ground shipping on orders over $150; same-day expedited (UPS Next Day Air, FedEx Priority) available at checkout.
The 3859D is a Dell power supplies & power protection component with power 410W, voltage 240V. Pro Disk Network sells the 3859D for $100.00 with same-day US shipping and a 30-day free return guarantee.
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Reviewed by:Pro Disk Network Engineering Team — . Specifications, compatibility, and pricing for the 3859D verified against the manufacturer datasheet and our internal lab benchmarks.
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Same-Day US Shipping — orders before 3pm ET ship today via FedEx/UPS
30-Day Free Returns — pre-paid label included on all US orders
Net 30 Available — for verified business buyers
2,000+ B2B Customers — MSPs, government, education, enterprise IT
The 3859D is a Dell power supplies & power protection part. Email sales@prodisknetwork.com with your system make, model, and serial number - we will confirm compatibility and ship same-day if in stock.
How fast does the 3859D ship?
If in stock, the 3859D ships same business day on US orders placed before 2 pm ET. Most US ZIP codes receive next-business-day or 2-day delivery via FedEx/UPS Ground or Express. Bulk and project orders shipping in pallets are typically dispatched within 24-48 hours.
The 3859D is deployed by US enterprises, MSPs, government, and education customers across multiple infrastructure scenarios. Below are the most common deployment patterns Pro Disk Network sees in real-world orders.
Redundant Server Power — N+1 PSU configurations in dual-feed racks — order matched units in pairs to maintain hot-spare semantics.
Rack PDU Replacement — Vertical or horizontal PDUs in cabinet retrofits. Metered or switched models for granular outlet-level control.
Branch UPS — Office or remote site UPS. 1500–3000 VA covers most server-rack mini-deployments with 5–15 minute runtime.
Datacenter UPS Module — Online double-conversion UPS for production server rooms. Match VA rating to total connected load + 30% headroom.
New, Bulk, or Refurbished — Choosing Your Tier
Pro Disk Network offers the 3859D across three procurement tiers. Each tier is fully functional and warranted; the choice comes down to budget, warranty length, and whether the deployment is production-critical or capacity-expansion.
Tier
Discount vs OEM List
Warranty
Best For
New (Sealed OEM)
25–40%
Dell manufacturer warranty (1–5 yr)
Production-critical first-tier
New (Bulk OEM)
50–65%
3-year Pro Disk Network warranty
New cluster builds, secondary tier
Refurbished
75–85%
12-month advance replacement
Capacity expansion, lab, dev/test, EOL refresh
Bulk & Volume Pricing for 3859D
Ships from our Orlando, FL warehouse — same-day US dispatch on orders placed before 2pm ET. Net 30 terms available for verified businesses, government and education.
Volume discounts on the 3859D are automatic at checkout. Net 30 terms available for verified businesses, government, and education. Email sales@prodisknetwork.com for orders above 100 units.
Quantity
Discount
Unit Price
1
0%
$100.00
5+
4%
$96.00
10+
8%
$92.00
25+
13%
$87.00
50+
18%
$82.00
100+
23%
$77.00
What is the 3859D?
The 3859D is a Dell server power supply unit with power 410W and voltage 240V, manufactured by Dell. Pro Disk Network ships this part new and certified-refurbished from our US warehouse with same-day dispatch on orders placed before 3 PM ET, backed by a 30-day return guarantee.
Pros & Cons of 3859D
Pros
Hot-swap capable — no chassis power-cycle required
Redundant N+1 configuration support
Output rail efficiency verified at 50% load
Cons
Server-grade PSU — not for desktop or workstation use
Higher in-rush current — confirm UPS sizing
Single-PSU purchase misses matched-pair discount
Frequently Asked Questions about 3859D
Is the 3859D a genuine Dell part?
Yes. Pro Disk Network sources every 3859D as factory-original Dell inventory verified against the manufacturer parts registry before listing. New units arrive sealed in OEM packaging; refurbished units are pulled from decommissioned Dell servers, surface-tested, and re-warranted by Pro Disk Network for 12 months.
Will the 3859D fit my system?
The 3859D is a Dell power supplies & power protection part. Email sales@prodisknetwork.com with your system make, model, and serial number - we will confirm compatibility and ship same-day if in stock.
How fast does the 3859D ship?
If in stock, the 3859D ships same business day on US orders placed before 2 pm ET. Most US ZIP codes receive next-business-day or 2-day delivery via FedEx/UPS Ground or Express. Bulk and project orders shipping in pallets are typically dispatched within 24-48 hours.
What is the warranty on the 3859D?
New 3859D units carry the full Dell manufacturer warranty (typically 1 to 5 years depending on product line). Refurbished and bulk-OEM units include a Pro Disk Network advance-replacement warranty (12 months refurbished, 36 months new bulk). DOA replacement is free within 30 days of receipt.
Do you offer bulk pricing for the 3859D?
Yes. Pro Disk Network offers automatic volume discounts at 10, 25, 50, and 100+ unit tiers. Net 30 terms are available for verified businesses, government, and education buyers. Email sales@prodisknetwork.com with the quantity and target ship date for a quote within one business day.
Pro Disk Network Buyer’s Guide: Power Supplies & Power Protection
PSU Sizing: Connected Load, Efficiency Curves, and N+1 Redundancy
Sizing the 3859D or its replacement starts with calculating connected load. Add up the nameplate wattage of CPUs, GPUs, drives, fans, and add-in cards under maximum sustained load. Idle is irrelevant; peak sustained is what matters. Size the PSU at 60-80% of nameplate load for best efficiency — modern Platinum/Titanium PSUs hit peak efficiency at 50% load and degrade above 80%.
AC Input, Phase Balancing, and Datacentre Power Best Practices
For UPS-fed servers, confirm the UPS output waveform is compatible with the 3859D's input. Modern PSUs accept both sine-wave and high-quality simulated sine-wave inputs, but older or stepped-approximation UPS outputs can cause buzzing or premature PSU failure. When in doubt, use double-conversion online UPS units.