Chris Cutler of Riello UPS explains why regular maintenance is crucial to the long-term performance of your uninterruptible power supplies and outlines the benefits of giving a bit of TLC to your UPS.
Uninterruptible power supplies offer you that ultimate protection against unplanned downtime. Whether it’s in a mission-critical setting such as a data centre or hospital, or in a sports stadium, office or shop, they work away in the background to help keep your vital equipment and systems running.
But once you’ve got your UPS protection in place, there’s no room for complacency and the worst thing you can do is think you’ve got everything sorted so you can forget about it.
That unit is a sophisticated piece of kit in its own right. It’s probably cost anywhere from a few hundred pounds for the smallest system, through to tens or even hundreds of thousands of pounds for larger installations.
To get the best out of such an investment, you need to look after it. Wear and tear over time is unavoidable. It goes without saying that if your UPS and batteries aren’t well maintained, you’re taking an unnecessary gamble that it won’t work correctly when you need it most, with all the disastrous consequences that a dropped load can bring.
However, adopting a proactive approach to maintenance offers much more than simply reducing your risk of failure. It ensures your UPS runs more efficiently, which in turn reduces power consumption. It also maximises the lifespan of the system, which optimises your total cost of ownership (TCO).
That’s why mission-critical sites such as data centres tend to opt for an ongoing maintenance plan. These agreements spell out the emergency response time for engineers to attend site in the event of something going wrong. They also include provision for at least one Preventive Maintenance Visit (PMV) a year.
Even for UPSs that aren’t covered under a maintenance contract, regular service visits are highly recommended. It’s similar to getting an annual ‘health check’ for your car or boiler – it provides that peace of mind that everything’s working properly.
Competence is critical
We’ll get to the nitty-gritty of what a PMV should include shortly. But firstly, let’s tackle the thorny question of who is going to carry out the service visit.
As touched on above, a UPS is a complex electrical device that needs handling with care. Your general maintenance or electrical engineer is unlikely to have the product-specific knowledge to carry out the task.
Someone who isn’t familiar with a UPS can easily carry out service procedures in the wrong order or accidentally throw an incorrect switch – never forget that human error is the most common cause of downtime. Also bear in mind that many product warranties are invalidated if the UPS isn’t maintained correctly.
However, you don’t necessarily need to go straight to the manufacturer to arrange a service visit. What’s important is whether the engineer is competent and fully trained on the particular UPS you have.
Before any PMV on your UPS, remember to ask for proof the engineer is trained and certified for the specific manufacturer and UPS model. Don’t forget, sub-contractors are often substituted at the last minute if the originally scheduled engineer is unavailable, so it’s always worth double-checking.
The ABCs of a PMV
Engineers will typically kick-off a maintenance visit with a thorough visual inspection of the unit and its key components for any obvious signs of wear and tear. They’ll also take a close look at the batteries for swelling, corrosion, damage or leakage.
Next up, the engineer will check all the electrical connections as some may have started to come loose and need a bit of tightening up. This element focuses on circuit breakers, contactors, fuses, cabling, transformers, PCBs, fans, capacitors and the UPS’s communications slots.
Most UPS maintenance providers these days use thermal imaging cameras for this. Heat is a tell-tale sign of a loose connection, and no matter how experienced the service engineer, this more advanced technology can detect ‘hotspots’ better than the human eye or touch.
It’s also important to check the battery terminal connections and make sure they’re at the correct torque setting.
Next on the agenda is a series of mechanical tests of the UPS’s functionality. This includes downloading historical operating and alarm logs for analysis, along with testing the unit across a range of operating modes to see whether everything runs as expected.
Mission-critical environments such as a data centre may require more in-depth functional testing. This could include using load banks that allow the engineer to test the UPS and batteries across a range of simulated loads without ever putting the critical loads at risk.
A thorough PMV should also examine the installation environment and whether there’s anything that could damage the UPS or speed up the rate of component deterioration. These factors include a build-up of dust, excessive heat or humidity, and poor ventilation.
In an ideal world, these issues would have been ironed out during the initial design, installation and commissioning stage. But circumstances change, and the day-to-day environment might be significantly different from when the UPS was installed or even since the previous service visit.
The PMV also provides the perfect opportunity for the engineer to install any necessary firmware updates. Making sure your UPS has the latest software is an easy – but sometimes overlooked – way to ensure it runs at its best. Not only can this have a positive impact on performance and reliability, but firmware updates can also improve the energy efficiency of the unit.
Once the engineer has finished all the tests, inspections and system updates, their final task is to fill out a detailed service report. This includes all the readings from the PMV, as well as a comprehensive rundown of any potential faults and recommended remedial actions, for example, listing any consumables that are due for replacement.
Prevention is better than cure
When it comes to UPS maintenance, a basic rule of thumb is that preventive action is far more effective – and less costly in the longer term – than being reactive.
Let’s take UPS batteries as an example. Typically they’ll have either a five or 10-year design life. But best practice shows that it’s best to proactively replace them in service years three to four (for five-year) or seven to eight (for 10-year), as this significantly reduces your risk of failure.
One of the outcomes of a PMV might be to recommend a similarly pre-emptive approach to capacitors and fans, two other key components of your UPS.
Replacing these ageing parts is known as a UPS Overhaul, which is basically a cost-effective way to extend your unit’s service life. Not only do the new capacitors and fans lower the likelihood of you experiencing a major system failure, but they also offer a much-needed boost in terms of reliability, performance and efficiency.
By taking a proactive approach to UPS maintenance, you’re not only optimising your total cost of ownership (TCO) over the lifespan of your UPS, you’re also far less likely to suffer damaging equipment downtime or be forced into the more expensive option of replacing an entire UPS.
