There can be no doubt that a UPS is essential for the majority of businesses, especially given today’s power problems, writes Elrica Quick, APC product specialist at Drive Control Corporation.

However, many businesses have already invested in UPS solutions for a number of years. These units typically have a lifespan of between five and 10 years, depending on a number of different influences, and have to be replaced at some point. However, the question of when to replace an older UPS with a new one is not always straightforward.

A UPS, like any other electronic equipment, does not have an unlimited lifespan and organisations need to make a decision as to what to do when reaching its ‘life expectancy’. Organisations can simply replace the old UPS with a new one, they can upgrade it to extend life and performance for a few more years, or they can run it until it fails completely, doing nothing other than basic maintenance. Each of these scenarios has its own pros and cons and would be applicable to a certain set of circumstances.

When it comes to this decision, there are many factors to consider, with the primary ones being the present UPS conditions and capabilities, as well as future requirements and constraints. Evaluating the current situation and determining future needs is essential. Firstly, it is important to establish whether or not the legacy UPS is or will soon be unable to meet its performance requirements and if it can be upgraded. If the unit has been discontinued, spare parts are unavailable, excess maintenance is required, or the UPS cannot meet critical performance requirements, this then indicates that a UPS is at or near the end of its usable life and should be replaced.

However, if the UPS is meeting the load and runtime requirements, an organisation could choose to leave it in service and run it to failure in an attempt to gain maximum return from existing investment. This may be a risky path, as there is no way to determine exactly when a UPS will fail, and so careful planning is necessary to minimise the impact of the UPS’s imminent and inevitable failure.

If the UPS is not at the end of its service life for the intended application, the next step is to evaluate the UPS according to a number of factors, including energy efficiency and future load requirements. The efficiency of the UPS system determines the operating cost to a large extent. It is therefore important to understand how efficiently the UPS operates today and how it can be improved through upgrades, changed load requirements, or by replacing with new units. These energy savings should be accounted for in the decision process, and the current efficiency compared to the efficiency of the new UPS being considered to determine potential savings and improvements.

Future load requirements are based on how the IT load is expected to change over time. This should also be a significant influencing factor in the decision of whether to keep, upgrade, or buy new UPSs. If the existing UPS system is at or near full load and future load growth is anticipated, options to add capacity must be explored, such as adding more power modules, if the until allows, or replacing with another UPS unit. Obviously, if the existing UPS capacity cannot be changed to meet the future requirements, then buying a new UPS is an option.

The new UPS could also be used in conjunction with the old UPS in order to share the load.  On the other hand, if the existing units are lightly loaded, then buying new or performing upgrades may not be necessary. If the load growth is minimal, it may be possible to replace with smaller units. Downsizing the UPS would improve efficiency and likely lower service costs.

Assuming the UPS does not unexpectedly fail or drop the load, run to fail is the lowest cost option. However, the risk of sudden failure and impacting the load is higher. Upgrading is often a viable option, and many manufacturers offer services to modernise older UPSs to extend their service life. What can be upgraded or replaced in a UPS varies depending on the manufacturer and model, and the disruption to business depends on the modularity of the UPS and how easily upgrades can be performed. Completely replacing a legacy UPS carries a high risk of disruption during the changeover, but the long-term risk profile is low. Initial capital expense will obviously be higher, but this can often be balanced out by reduced operating expenses as a result of improved efficiency, right-sizing of equipment and lower service costs, amongst others.

The decision on what to do with an older UPS is not always obvious or straightforward, and each option mentioned above has its own merits. There is no one right answer to the question, but a number of options may be applicable depending on various factors. Organisations need to determine current and future capacity, redundancy and efficiency requirements and more. Understanding the current situation and future requirements will largely determine whether it makes sense to run to fail, upgrade, or buy new.