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Safeguard data center power with regular UPS maintenance
There are several levels of testing to address when developing a UPS maintenance checklist. Be sure to conduct visual, thermal and load tests to verify UPS health.
Data center power infrastructure maintenance is essential for operational continuity. In addition to regular battery health evaluation, you should also develop a maintenance plan for backup power options such as uninterrupted power supplies.
This type of preventive maintenance plan can not only reduce the amount of surprise expenses, but also ensures that your data center will still have power in case of an emergency or unexpected outage.
Although the specifics of an uninterrupted power supply (UPS) maintenance checklist vary from one organization to the next, there are a few main areas that your team should address as part of regular operations or through a service provider.
Periodic visual inspections are some of the most important steps you can take to keep your UPSes healthy. You can perform a partial visual inspection and look at the unit's exterior, but a fully comprehensive inspection includes an internal component examination.
Doing so, however, can expose you to dangerous electrical currents. Such inspection should, therefore, only be performed by qualified individuals, such as an electrical engineer, facility electrician or a third party.
For a partial visual inspection, look for any buildup of dust or dirt. Dust can clog device vents and cause them to overheat. The inspection should also include a battery assessment. Look out for any signs of corrosion, leakage or swelling, as these are indicators that the batteries need replacement.
It is also a good idea to check the alternating current input and output capacitors, as well as the direct current filter capacitors. The capacitors should be clean and not show any signs of cracking or swelling.
During a visual UPS maintenance inspection, don't only use your eyes. You should also listen for unusual sounds and pay attention to abnormal smells; either could indicate the presence of a hardware problem.
Another important UPS maintenance task is a thermal scan that checks the temperature around the UPS to ensure that it is within the manufacturer's operating specifications.
One way to inspect UPS temperature is to use a noncontact, infrared thermometer to measure the surface temperature of the chassis. If your UPSes are fan-cooled, then you can also use a thermometer to check the temperature of the air that exits the units.
If your organization has a large number of UPSes to check, a thermal imaging camera may be more efficient to use. A thermal imaging camera creates a heat-based picture that makes it very easy to locate thermal anomalies among your UPS systems.
Load and load bank testing
Load tests are essential for UPS maintenance. A load test verifies the UPS' ability to power your data center hardware in the event of a power failure and how much power the supply can support. Load tests require careful planning so they don't jeopardize production workloads.
There are several different types of load tests, some of which require specialized knowledge and should only be performed by a qualified technician. Load tests may involve more than simply a battery rundown. Common load test types include steady-state load tests, harmonic analysis and a transient response load test.
Though tests have similar names, a load test and a load bank test are different procedures.
Like a load test, a load bank test verifies the UPS' ability to provide a predetermined amount of sustained power. These tests use specific hardware known as load banks to test UPS batteries. These banks provide the different power levels to test the UPS; load bank tests do not analyze the unit's overall ability to power data center hardware.
An important consideration for load bank tests is that load banks are similar to heating elements. As such, you must perform load bank testing with fire safety in mind, and away from any alarms or sprinklers.
If you perform either a load test or a load bank test, it is essential to make sure that the UPS batteries are fully charged during testing. Otherwise, the test results are invalid.
Alarm verification and UPS calibration
Another important maintenance task is to periodically verify that each UPS is properly communicating with your monitoring software. While you are at it, review each UPS' alarm log for any indication that the UPS might be experiencing abnormal behavior.
A trained technician should periodically make sure that UPS units are properly calibrated. A UPS that is not correctly calibrated can trigger a voltage overage alarm, even if the supported load is well within what the device's power rating range. It may also cause the unit to display incorrect runtime data, which makes it harder to schedule required maintenance.
As important as proper UPS maintenance may be, UPS maintenance is not a replacement for the hardware refresh cycle. UPS batteries, even if unused, have a limited lifespan. As such, UPS batteries should be periodically replaced according to the manufacturer's recommendations.