When does a UPS reach the end of its life?

Why plan for end of life before the UPS fails?

Because the failure that ends a UPS usually starts in a part that was due. Eaton notes that every maker's three-phase UPS can theoretically run for 15 and even 20 years with proper maintenance, but that internal electronic components can wear out much earlier, especially outside the recommended operating conditions, and that UPS failures account for one-fourth of unplanned data-centre outages. For a UPS 10 years or older, Eaton sets out three options: replace the UPS, update its internal electronics, or run it until it fails. A plan makes that choice deliberately, with the dates in front of the owner. The replacement project itself is covered in modernization and replacement planning; this guide covers how the dates are found.

What do the service-life notices mean?

They tell you how long the maker will support the model. Eaton's end-of-service-life table uses four stages: Active (full parts and labour coverage), Mature (best efforts, parts may not be available, product replacement recommended), Retired (no contract coverage, time-and-material service only) and End of Service Life (no service or parts, replace the product). Mitsubishi Electric describes the same path: as components become obsolete, it eventually becomes no longer feasible to provide parts and support for legacy products, with a best-effort phase until the announced end-of-support date. An audit records the stage of every UPS on site and the date of the next stage.

Which UPS parts are replaced on a cycle?

The figures are from Eaton's aging-UPS paper and apply to its designs under nominal conditions; other makers publish their own, and the manual for each model comes first. Eaton notes that where capacitors sit inside the power modules, their service life is 11 years with replacement recommended at 10, which lines up with replacing the unit's electronics as a whole.

Why do capacitors and fans matter so much?

Because they fail quietly and take other parts with them. Eaton advises treating capacitors as the perishable commodity they are and planning to replace them at or near the end of their rated service life, and notes that heat accelerates wear on capacitors, circuit boards and wiring insulation. A fan that has slowed lets heat build inside the cabinet, which shortens the life of everything around it. Eaton also notes that dust can block air filters and shut a UPS down on overheating, and recommends inspecting the filters every month.

How is battery age assessed?

By date and by test, not by date alone. Eaton's table puts the recommended replacement of VRLA batteries at 4 years on average, and of lithium batteries at 10, but the actual condition depends on temperature, cycling and how the batteries were stored. C&D's maintenance manual gives a practical yardstick for the ohmic readings taken at each visit: changes over time of less than ±20% are acceptable, while changes greater than 50% call for further attention such as a load test. An audit records the install date, the last readings and the trend for every string. How long batteries last and why is covered in UPS battery life.

How does an audit turn the dates into a plan?

• List every UPS with its model, install date and service-life stage
• For each, list the batteries, fans, capacitors and filters with their install or last-replacement dates
• Mark what is past its recommended replacement now, and what falls due in the next maintenance cycles
• Price the options for each UPS: replace the parts, update the electronics, or replace the unit
• Line the work up with the site's maintenance windows and the capacity review

The output is a dated plan, so budget and outage windows can be set years ahead rather than after a failure. It also feeds the capacity review, because a replacement is the moment to resize, and it becomes a section of the audit report.

What if a UPS is past every date?

Then the plan protects the load until it can be replaced. Eaton warns that keeping a UPS of 10 years or more in service can mean higher service and repair costs, harder-to-find parts and limited emergency resources, depending on when the model was introduced. Until the replacement is installed, the usual measures are a confirmed spare-parts position for the parts most likely to fail, more frequent inspection of fans and filters, battery testing at shorter intervals, and a bypass procedure that the site has rehearsed. Each measure goes into the plan with its own date, so a unit past its life is managed rather than simply left running.

Can end-of-life planning be quoted?

Yes. Send the UPS list with models, serial numbers and install dates, and the last maintenance report if you have one, through the audit quote request. For batteries due for replacement, data-centre UPS batteries lists the formats; for the replacement itself, UPS service for data centres.

Related pages

• Data-centre audits and planningTier claims, capacity, end of life and the report.
• Is your UPS redundancy still real?Load per module and per path, against what remains after a loss.
• UPS modernization and replacement planningRemaining life, end of support, refresh or replace.
• How long do UPS batteries last?Real life, temperature, charging and the signs.