Uniqcli

Best Online Double-Conversion UPS Systems

Always-on UPS topology for critical loads — read by VA and watt rating, rack or tower form factor and network-card support, with live pricing per row.

Online double-conversion UPS in stock at Uniqcli

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A curated selection with live pricing — in-stock lines first, then back-ordered lines with a typical lead time. Every line is sourced through US distribution and screened for NDAA §889 status before checkout, with TAA verified on request.

700VA, tower

Eaton

Tripp Lite by Eaton series SmartOnline 120V 700VA 630W…

SU700XLCD

A 700VA/630W SmartOnline double-conversion UPS in a tower chassis with six outlets, an LCD and a network-card option, for a small rack of critical gear.

$1,090.20In stock
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500VA, 2U

Vertiv

Vertiv Liebert GXT5 UPS

GXT5-500LVRT2UXL

A 500VA/500W Liebert GXT5 online double-conversion UPS in a 2U rack/tower chassis with a colour graphic LCD and an optional network card.

$1,184.15In stock
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750VA, 2U

Vertiv

Vertiv Liebert GXT5 UPS

GXT5-750LVRT2UXL

A 750VA/750W Liebert GXT5 online double-conversion UPS, rack/tower convertible in 2U with a graphic LCD and extended-runtime capability.

$1,295.40In stock
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1440VA, 1U

Eaton

Tripp Lite by Eaton 120V 1440VA 1440W Double-Conversion Smart Online UPS

SU1500LCD1U

A 1440VA/1440W SmartOnline double-conversion UPS in a space-saving 1U rack chassis with five outlets, an LCD and a management-card slot.

$1,463.72In stock
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750VA, 2U network

Eaton

Eaton Tripp Lite Series SmartOnline 750VA 675W 120V Double-Conversion…

SU750RTXLCD2UN

A 750VA/675W SmartOnline double-conversion UPS in 2U with extended run, eight outlets and a network card included for graceful shutdown and monitoring.

$1,855.64In stock
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1000VA, 2U

Vertiv

Vertiv Liebert GXT5 UPS

GXT5-1000LVRT2UXL

A 1000VA/1000W Liebert GXT5 online double-conversion UPS in a 2U rack/tower chassis, Energy Star rated with a colour graphic LCD.

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1000VA, 2U, TAA

Vertiv

Vertiv Liebert GXT5 TAA UPS

GXT5-1000LVRT2UXLTAA

A 1000VA/1000W Liebert GXT5 online double-conversion UPS in 2U with a unity output power factor, listed TAA Compliant in the manufacturer's own title.

TAA Compliant is stated on this row's own title — a per-part fact to confirm on the model you order.

$1,560.58In stock
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1500VA, 2U network

Eaton

Tripp Lite by Eaton series UPS SmartOnline 1500VA 1350W 120V…

SU1500RTXLCDN

A 1500VA/1350W SmartOnline double-conversion UPS in a 2U rack/tower chassis with extended run and a network card included for monitored shutdown.

$2,518.96In stock
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1500VA, 2U, TAA

Vertiv

Vertiv Liebert GXT5 TAA UPS

GXT5-1500LVRT2UXLTAA

A 1500VA/1350W Liebert GXT5 online double-conversion UPS in 2U with a colour graphic LCD, listed TAA Compliant by the manufacturer.

$2,058.92In stock
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2000VA, 1U

Eaton

Tripp Lite by Eaton 120V 2000VA 1600W Double-Conversion Smart Online UPS

SU2000LCD1U

A 2000VA/1600W SmartOnline double-conversion UPS in a dense 1U chassis with five outlets and an LCD, for a rack where U space is tight.

$1,690.96Back-ordered
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2000VA, lithium

Eaton

Eaton 9PX 2000VA 1800W 120V Online Double-Conversion UPS

9PX2000RTN

A 2000VA/1800W Eaton 9PX online double-conversion UPS in 2U with extended run and a cybersecure network card, from the 9PX line for mission-critical loads.

$3,756.36In stock
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3000VA, 2U

Vertiv

Vertiv Liebert GXT5 UPS

GXT5-3000LVRT2UXL

A 3000VA/2700W Liebert GXT5 online double-conversion UPS in a 2U rack/tower chassis with a graphic LCD, for backing a loaded rack of equipment.

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More UPS systems in the Uniqcli catalog

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More from across this category. In-stock lines lead, and a back-ordered line carries the same estimated availability its product page does — with live pricing throughout, NDAA §889 screening before checkout and TAA verified on request.

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An online double-conversion UPS is the topology that never hands the load a break. It continuously converts incoming AC to DC and back to a clean sine wave, so the protected equipment always runs off the inverter and there is no transfer time when utility power fails — the battery is already in the path. That is the difference from a line-interactive UPS, which passes utility power through until it drops and then switches to battery in a few milliseconds. For a server, a storage array or network core that difference is the argument for double-conversion. Every row on this page states double-conversion, or online, in the manufacturer's own title.

The rating that sizes the unit is the pair of numbers on the title: VA and watts. Watts is the real work the UPS can deliver and the figure to size the load against; VA is the apparent power, and on these online units the two are close because the power factor is high. The parts here run from 500VA desktop and small-rack units up to 3000VA machines that back a loaded rack, and picking the rating is a matter of adding the nameplate draw of the protected equipment and leaving headroom rather than buying to the exact number.

Form factor and management are the next decisions. Most of these are rack/tower convertible in a 1U or 2U chassis, so the same unit stands in a tower or racks in a cabinet; and most take a network management card — included on some, an option on others — that puts the UPS on the network for shutdown, alerting and monitoring. Where a purchase order names TAA, some of these systems state TAA Compliant in the manufacturer's own title and others do not, and a few name a lithium-ion battery — both are per-part facts to read on the exact row. Send the load's wattage, the rack space and whether you need a network card, and the UPS, the runtime and any extended-battery modules can be quoted on one document.

Buyer's checklist

How to choose an online double-conversion UPS

  • Buy for the topology first. An online double-conversion UPS runs the load off the inverter continuously, so there is no transfer time when utility power fails — the reason it is specified for servers, storage and network core over a line-interactive unit. Every title here states double-conversion or online.
  • Size against the watt rating, not the VA. Watts is the real power the UPS can deliver; add the nameplate draw of the protected equipment and leave headroom. On these online units VA and watts are close because the output power factor is high.
  • Match the form factor to the space. Most are rack/tower convertible in a 1U or 2U chassis — the same unit towers on a floor or racks in a cabinet. The chassis height is stated in every title.
  • Decide the management. A network management card puts the UPS on the network for graceful shutdown, alerting and monitoring; it is included on some units here and an option on others, stated in the title.
  • Plan the runtime separately from the rating. Runtime depends on the battery and the load, and several of these accept extended-battery modules — decide the minutes you need at your load and size the battery to it, not just the VA.
  • Standardise the platform per role so the network card, the shutdown software and the spares stay one decision across the estate, and order the extended-battery modules with the UPS where the runtime needs them.
  • Where the order names TAA or a lithium-ion battery, read it on the part number. Some of these systems carry TAA Compliant or a lithium-ion battery in the manufacturer's own title and others do not — per-part facts to confirm on the exact row.

Why online double-conversion, and what zero transfer time buys

Every UPS bridges a power failure; the topologies differ in how. A line-interactive UPS passes utility power through to the load, correcting voltage sags and surges as it goes, and switches to its battery inverter when the utility drops — a transfer that takes a few milliseconds. An online double-conversion UPS does not pass utility power through at all: it converts the incoming AC to DC and back to a fresh sine wave continuously, so the load always runs off the inverter and the battery is already in the path when the utility fails. The transfer time is effectively zero because there is no transfer — the output was never the raw utility to begin with.

For most office equipment the line-interactive few-millisecond switch is invisible and fine. For a server with a sensitive power supply, a storage array mid-write, or a network core, the case for double-conversion is that the output is a continuously regenerated waveform isolated from whatever the utility is doing — brownouts, frequency drift and switching noise are absorbed by the conversion rather than passed along. That is why this topology is the default for critical IT loads and why every unit on this page states double-conversion, or online, in the manufacturer's own title. The trade is efficiency and cost — the double conversion runs continuously — which is why it is reserved for the loads that need it.

Sizing, runtime and management

Sizing an online UPS starts with watts. The two numbers on the title, VA and watts, describe apparent and real power; watts is the work the UPS can actually deliver and the figure to size the protected load against. On these online units the two are close because the output power factor is high, often near unity, so a 1500VA unit delivers close to 1500W rather than the lower real figure an older unit with a 0.6 power factor would. Add the nameplate draw of everything the UPS protects, leave headroom for inrush and growth, and pick the rating above that sum rather than at it.

Runtime is a separate decision from the rating, because it depends on the battery and the load together — the same UPS runs longer on a light load than a heavy one. Several of the units here accept extended-battery modules, so where a role needs minutes rather than seconds you size the battery to the runtime you actually need. Management is the last piece: a network management card, included on some units and an option on others, puts the UPS on the network for graceful server shutdown, email alerting and load monitoring, which is what turns a battery in a rack into a managed part of the infrastructure. Send the load wattage, the rack space, the runtime target and whether you need the network card, and the UPS and its batteries come back on one quote.

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FAQ

Common questions

What is an online double-conversion UPS?
It is a UPS topology that runs the protected load off its inverter continuously. Incoming AC is converted to DC and back to a clean sine wave without interruption, so the equipment always runs off the regenerated output and the battery is already in the path when utility power fails — there is effectively no transfer time. That is the difference from a line-interactive UPS, which passes utility power through and switches to battery in a few milliseconds when it drops. Every unit on this page states double-conversion, or online, in the manufacturer's own title.
How is double-conversion different from a line-interactive UPS?
A line-interactive UPS passes utility power through to the load, corrects voltage sags and surges, and switches to its battery inverter in a few milliseconds when the utility fails. An online double-conversion UPS never passes the raw utility through — it continuously rebuilds the waveform, so the output is isolated from brownouts, frequency drift and switching noise, and the transfer time is effectively zero. Line-interactive is fine for most office equipment; double-conversion is specified for servers, storage arrays and network core where the load is sensitive and cannot tolerate even a brief transfer.
How do I size a double-conversion UPS?
Size against the watt rating, not the VA. Watts is the real power the UPS can deliver, so add the nameplate draw of everything it protects and pick a rating above that sum with headroom for inrush and growth. On these online units VA and watts are close because the output power factor is high, so a 1500VA unit delivers close to 1500W. Runtime is a separate calculation that depends on the battery and the load — decide the minutes you need at your load, and where several of these accept extended-battery modules, size the battery to that.
Do these UPS units come with a network management card?
Some do and some take it as an option — the title states which. A network management card puts the UPS on the network for graceful shutdown of the protected servers, email and SNMP alerting, and load and battery monitoring, which is what makes a rack UPS a managed part of the infrastructure rather than a standalone battery. On the units here the card is included on some models and a slot option on others. If network shutdown and monitoring matter, confirm the card on the exact part number or add it to the order.
Can business, government and education buyers order these?
Every line Uniqcli quotes is sourced through US distribution and screened for TAA country-of-origin and NDAA §889 status before checkout — with documentation tied to the specific part number, not a product family.
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