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Dell NH493 Power Supply for Dimension E521/E520 Desktop (L305P-01)
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Dell NH493 Power Supply for Dimension E521/E520 Desktop (L305P-01)

Bottom line: The Dell NH493 Power Supply for Dimension E521/E520 Desktop ($49.01 on Amazon as of 2026-10-06): 305W rating matches Dell OptiPlex 330/360/740/745/745C/755 factory spec; main trade-off: proprietary Dell form factor and pinout, so it fits nothing outside those models.

$49.01

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Buy on Amazon — $49.01 Compare to similar power supplies

By , Founder & Editor-in-Chief · Listing data updated

Mike Perry — Hardware researcher since 2014, focused on GPU performance across gaming, rendering, and local-LLM inference. Synthesises community benchmarks, manufacturer specs, and public forum data into actionable buying guides.

*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.

Pros & Cons

Pros

  • ✓ 305W rating matches Dell OptiPlex 330/360/740/745/745C/755 factory spec
  • ✓ Genuine Dell part NH493 (L305P-01), not a generic aftermarket substitute
  • ✓ Active PFC keeps line power draw cleaner than older no-PFC units

Cons

  • ✗ Proprietary Dell form factor and pinout, so it fits nothing outside those models
  • ✗ 305W ceiling rules out modern discrete GPUs that need a PCIe power lead
  • ✗ No modular cabling: fixed harness clutters small Dimension and OptiPlex cases
  • ✗ Listing omits rail amperage, connector counts, and efficiency rating

Manufacturer description

305 WATT, PFC FOR OPT 330/360/740/745/ 745C/755--, POWER SUPPLY; Part Number: NH493; Category: Power Supplies; Subcategory: Power Supply

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SpecPicks Verdict

SpecPicks scored Dell NH493 Power Supply for Dimension E521/E520 Desktop using a rating × review-volume × price-fit model applied to published specs and reviews across the power supplies category. Dell's power supplies lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.

Common buyer scenarios for power supplies of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.

Key Features

  • 305 WATT
  • PFC FOR OPT 330/360/740/745/ 745C/755--
  • POWER SUPPLY
  • Power Supply
  • Power Supplies

Full Specifications

BrandDell
Wattage305.00
Model Namenh493
Form FactorInternal
Model NumberNH493
Connector TypeSATA
Cooling MethodAir
Number of Fans1
Output Wattage305 Watts
Item Dimensions1.1 x 9.7 x 6.5 inches
Mfr Part NumberNH493
Compatible DevicesPersonal Computer
Connector Quantity10
Power Supply DesignInternal
Maximum Input Voltage120 Volts (AC)
Minimum Input Voltage110 Volts (AC)
Item dimensions L x W x H1.1 x 9.7 x 6.5 inches
System Bus Connector Type20+4 Pin
Connector Type Used on CableSATA
Global Trade Identification Number05704327684756

Ready to buy?

Dell NH493 Power Supply for Dimension E521/E520 Desktop (L305P-01) is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.

Buy on Amazon — $49.01

*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.

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Dell NH493 Power Supply for Dimension E521/E520 Desktop (L305P-01)
$49.01
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