Uninterruptible Power Supply (UPS) systems can have their effectiveness tested even prior to installation. Everything is OK! That guarantees that you won't have any unexpected losses or system faults in the future. It's really achievable.
In this guide, we will walk you through the process of testing a UPS step-by-step to ensure you grasp and are proficient in every important element.
We have started by outlining the preparatory phase, covering lightly what you should and shouldn't do to avoid hurting anyone, to make sure that everything goes smoothly.
How To Prepare For The Reliability Tests
Planning is the secret to success in all we do, including reliability testing of your UPS. Given that electricity is involved and that high power is typically dangerous, you should become familiar with the safety precautions in advance. Before starting the testing exercise, you should also list all the needed equipment and carry it to the location.
Some precautionary measures when handling electricity include ensuring your hands are dry and wearing protective clothing. Apparel such as gloves and heavy-duty dust coats protect you from potential acid spillages and physical injuries. Special gloves are also perfect for handling electricity, making them so instrumental when undertaking the tests.
Apart from the protective clothing, you’ll need devices to measure temperature, voltage, current, and the overall quality of the UPS power output. In brief, these are the essential devices:
- Infrared thermometer: measure temperature
- Ammeters: measure current
- Voltmeters: measure voltage
- Power analyzers: measure several parameters; a multipurpose device
- Load banks: measures UPS electrical load capacity
Also, take ample time to understand the major components and how they function. Only a comprehensive understanding will allow for proper testing and obtaining accurate results.
Here’s a rundown of the main components to give much attention when it comes to UPS’s reliability:
Crucial UPS Components for Reliability Checks:
- The inverter—An inverter converts direct current (DC) to alternating current (AC)and then steps it up to desirable voltage levels.
- The batteries—These are power storage banks that store the DC electrical energy the inverter converts for use during a power outage. Then during normal operation(when the utility supply is on), the batteries are recharged with power from the mains with the help of a rectifier.
- The display and control mechanisms—The display panel is the interface through which you monitor the various aspects of the UPS system. As for the control mechanisms, they allow you to conveniently enter desired settings into the system. Please note that most modern inverters have built-in control mechanisms to simplify the UPS system and make work easier.
So, How Do You Conduct a Reliability Test?
After the necessary preparations, next is to know and internalize the specific tests for your UPS reliability. We've classified the UPS tests into inverter and battery tests. This classification clarifies information and makes it easier to memorize.
Inverter Reliability Tests
Since the inverter is the main component of your UPS unit, you should know how to determine whether it's perfect or faulty. The following are the reliability tests to perform on your inverter before integrating it back into your UPS system.
The Maximum-Load Test
The maximum load test is vital in determining whether your inverter can support an electrical load equal to the maximum specified by the manufacturer. To conduct a maximum-load test on your inverter, you must first ensure your batteries are charged to capacity.
Such a test requires the use of recommended battery wires to connect the batteries to the inverter. You will also need a load bank device to simulate an electric load on the inverter.
To perform the test, connect the batteries to the inverter and switch it on. Once the inverter has run for a few seconds and the output power has stabilized, connect the load bank to the AC output and gradually increase the load to the maximum value specified by the manufacturer.
Let the inverter run the maximum load for at least 30 minutes while monitoring and recording the performance parameters such as voltage, current, and frequency using a power analyzer. A reliable inverter should maintain a stable power output with normal characteristics and should never overheat during the entire period.
The Endurance Test
Endurance is the measure of how long your inverter can run optimally without errors or failures. This test also requires a load bank, power analyzer, and timing device, like a stopwatch.
You start by powering up the inverter, letting it run to stabilize, and then connecting the load bank to the output. After that, you should raise the load bit by bit until it reaches the maximum.
Allow the inverter to run as long as possible while monitoring the output quality using the power analyzer to ensure that everything is okay. Note and record the time before the inverter overheats or automatically shuts down. The duration obtained is the inverter's endurance, and the longer it is, the more suitable the inverter.
The Environment Test
In UPS reliability testing, an environment test examines the inverter's ability to operate correctly in extreme environmental conditions, such as temperature and humidity.
This test might be a little trickier to conduct at home because you may need to simulate various humidity and temperature conditions accurately. So, in case you can't perform it at home, you can look for a certified nearby laboratory to complete it.
To test the inverter's reliability in various temperature conditions, you need a thermal camera, power analyzer, and oscilloscope. Next, put the inverter into the simulated environment and turn it on. Connect the load bank and set the temperature to the lower extremity.
Slowly adjust the load to the maximum and let the setup run for about 30 minutes while monitoring and recording the power quality using the analyzer, and the noise levels, using an oscilloscope. Do the same for the high extremity, then monitor and record your findings. Your inverter should operate optimally at the highest or lowest specified temperatures.
Please note that a humidity test will use the same setup above, except that you'll be varying the humidity level and not temperature.
The Transfer Test
The transfer test is another vital consideration when testing the reliability of your UPS unit. It determines how fast or slow your system can switch from the utility supply to the power supply should there be an outage or interruption.
To perform a transfer test, you'll ensure that the UPS unit is correctly installed with all its components and running efficiently. The most important thing is connecting it to the mains supply. You can perform an excellent transfer test by using power interruption injectors or turning off the utility grid and recording the time it takes for a complete shift to the UPS system. The ideal duration is always any value below 10 milliseconds.
Battery Reliability Tests
As with the inverter, you have some options to check whether your batteries can perform optimally. In this section, we've explained how to perform the two most crucial UPS battery reliability tests.
The Discharge Test
A discharge test measures how fast your batteries can discharge their power when fully charged. In other words, the discharge test determines how long your fully charged batteries would last if they were supplying current to the UPS unit.
Performing the discharge test requires charging the batteries to their maximum capacity upfront and then connecting them to the inverter. The next step is connecting the load bank to the inverter and raising the load to maximum. If everything is fine, your batteries should take the same number of hours indicated by the manufacturer while running the load before getting completely drained.
Note: Please disconnect your UPS from the utility grid before conducting a discharge test. If you don't, you will most likely get inaccurate results, and you may never really know the reliability of your batteries.
The Recharge Test
A recharge test helps you to figure out how long your batteries would take to get to maximum charge capacity. Before conducting this test, you must drain the batteries completely by connecting them to an inverter supplying power to the load bank.
Once the batteries have been drained completely, connect them to the UPS and turn on the utility grid to charge them. Please note and record the starting time and the time when they reach maximum capacity.
The time it takes your batteries to reach full capacity when being recharged is the difference between the starting and stopping times. The duration should be short because the batteries should recharge faster in readiness for a potential outage.
Why Test UPS System's Reliability?
Knowing the performance status of your UPS system has many advantages. For instance, testing ensures you install only what will meet your power demands. Imagine you realize your UPS backup cannot last long enough just after the utility grid goes off. How inconvenient would that be? Trust me, you don't even want to talk about it.
Conducting a reliability test also prevents possible damage to your UPS system. For instance, when you do a maximum load test and the inverter fails, you can replace it with a more capable one. Therefore, organizing a replacement prevents installing one that would blow out due to overheating.
A UPS reliability test also minimizes losses and accidents, thereby keeping future maintenance costs as low as possible. In other words, reliability tests let you spot mistakes way earlier before they happen and fix them as necessary.
Final Words
Testing the reliability of a UPS system involves simulating the actual operation scenarios and then examining the various performance indicators of the unit. The tests are conducted on the UPS system's two most critical components, the inverter and the batteries.
Reliability tests are significant because the results can be used to decide whether to proceed with the installation or invest in more robust components. This can prevent future damage and cut maintenance costs tremendously.
