What Does UPS Preventive Maintenance Include?

It depends on the manufacturer and the system, but most published scopes include a visual inspection of connections and subassemblies, capacitor inspection for leakage or swelling, fan and air filter checks, an environmental check, input, output, and bypass measurements, transfer and battery tests, firmware and advisory review, an alarm and event log review, a battery cabinet inspection, and a written report.

No single checklist applies to every UPS. Each manufacturer publishes its own PM scope, and it varies with the model and the size and type of system. Every major manufacturer checks capacitors and fans, but how deep the checks go and which parts are replaced differ. The right PM follows the manufacturer's procedures for your specific platform.

Most UPS systems receive PM annually to semiannually, depending on the manufacturer and how critical the load is. Eaton recommends annual PM, and Vertiv recommends two visits per year. NFPA 70B (2023 edition) makes a documented, condition-based maintenance program the expectation, so frequency should reflect equipment condition, age, and criticality as well as the manufacturer's schedule.

Usually not. PM inspects and tests these parts, but replacement is typically separate work. Eaton treats proactive replacement of batteries, capacitors, and fans as a life-extension service outside the PM, and Schneider Electric treats them as wear parts outside the PM. Ask what is included and what is quoted separately, including capacitors, fans, batteries, and load bank testing.

It depends on the manufacturer and the equipment. Eaton plans DC capacitors, AC capacitors, and fans for replacement around year 10 on its larger three-phase units. Vertiv publishes fan replacement at about 5 to 6 years and AC and DC capacitor replacement at about 6 or 12 to 15 years, depending on the equipment. Follow the published schedule for your model.

On modular systems such as the Eaton 93PM, Schneider Electric Symmetra PX, and Vertiv Liebert APM and EXM, capacitors and fans typically sit inside the swappable power modules. End-of-life service often means replacing the whole module rather than individual parts. On Symmetra PX, for example, power modules reach end of life at about 10 years and are replaced as modules.

Small single-phase units often use user-replaceable battery cartridges with a 3 to 5 year life, and in practice they are often replaced rather than maintained. Some manufacturers publish a shorter single-phase PM scope: Vertiv's covers voltages, thermal checks of breakers and connections, visual inspection, torque, cleaning, alarms, a transfer and battery discharge test, and battery float voltage and ripple.

No. A passing self-test does not prove runtime. IEEE 1188 for VRLA and IEEE 450 for flooded batteries call for regular inspections, ohmic (impedance or conductance) trending on VRLA quarterly to semiannually, and periodic capacity testing. Batteries should be replaced when capacity drops below 80% of rated, which a capacity test confirms.

Ask for the manufacturer's PM scope for your exact model, a clear list of what is included and what is separate (capacitors, fans, batteries, and load bank testing), the visit frequency, and a sample written report. Comp-Utility plans and performs PM in line with manufacturer recommendations. Call (512) 346-0999 or email sales@comp-utility.com to review your UPS fleet.

Call Comp-Utility right away at (512) 346-0999, and have the unit's model and serial number ready along with any alarm codes or messages shown on the UPS display. A unit in alarm can indicate a battery, load, or power-path issue that needs prompt attention. Because we maintain a large base of units under contract with the major UPS manufacturers, we can escalate directly to the right factory resources and coordinate service faster and more directly than a single end user calling general support, often getting you answers and a technician on site sooner.