During a recent site visit to provide a planned preventative maintenance (PPM), one of our engineers was drawn into a discussion about the customers existing UPS system and what features the on-site maintenance engineers would like to see in the future. They said they would like to convert to a modular UPS system, so that it is easily maintainable by themselves, and that if there ever was a problem with the UPS system, this could most probably be solved by the on-call engineer; simply swapping a faulty power module with a replacement from the on-site spares kit.
Since this customer has a number of UPS systems. If all systems used the same power modules then just keeping one or two power modules on site would in most cases provide an instantaneous fix.
A modular UPS system would also enable a capacity upgrade of the UPS. This can be achieved by simply adding additional power modules to the UPS system as long as the infrastructure cabling and switchgear has been sized accordingly; rather than having to purchase and install a brand new UPS system.