Making the right decision will depend on several unique factors . These factors include the criticality of the data centre , future load requirements , whether or not executives are planning to outsource some of the data centre operations , and whether cost savings surrounding energy efficiency are a factor .

Let ’ s look at the three decision scenarios to determine under which circumstances each decision makes the most sense :

‘ Making the right decision will depend on several unique factors ’

Run to fail

Under this scenario , the older UPS is kept in service until ‘ end of life ’ is reached . Assuming the UPS does not unexpectedly fail or drop the load , it is the lowest cost option with the least amount of disruption to day-today operations . However , the risk of sudden failure impacting the load is higher . As a UPS ages , maintenance costs will rise . Experience has shown that ‘ time & material ’ maintenance expenses more than double once a UPS reaches 10 years of age .

Although risk of downtime is increased under such a scenario ( especially if the overall degree of redundancy in the data centre is weak ), ‘ run to fail ’ serves as an appropriate option when no budget exists for either an upgrade or purchase of new equipment . In that case , what funds are available should be spent investing in a service contract that will handle sudden failures . If the facility will soon be consolidated or if a short term move to the cloud is anticipated , the ‘ run to fail ’ scenario may also present a sensible option .

Upgrade

Whether a UPS upgrade can be cost justified depends on the manufacturer and model of the particular UPS . Some UPSs are more modular and scalable than others . Typical parts and subsystems that are replaceable include battery strings , DC capacitors , fan assemblies , AC capacitors , Power supply units ( PSU ), intelligence modules and controller boards , inverter assemblies , static switches , rectifier SCR , and IGBTs . Compared

to the ‘ run to fail ’ scenario , downtime risk is reduced when the existing UPS is upgraded .

Upgrades are less time consuming than a ‘ buy new ’ scenario . An upgrade also presents less of a risk to the load . Upgrade tasks can be performed in a few hours with the UPS in maintenance bypass while the critical load is powered by the utility or a redundant power source .

Buy new

Replacing an older legacy UPS with a new UPS offers high short duration risk during the changeover , but the lowest longterm risk profile . Initial capital expenditures will be higher than performing an upgrade , but this needs to be balanced against the lower operating expenses ( such as lower service costs and higher efficiency performance ). Purchase of a new UPS becomes a more attractive option when the vendor of the existing UPS no longer offers support and spare parts are unavailable . Often with older UPS models , the capacity and efficiency ratings do not address current or future needs . In some regions , government incentives or tax discounts may exist for companies that install newer , high-efficiency UPSs . In some situations , the fear of system failure is so acute that only a new UPS can provide the peace of mind required to minimise high levels of stress .

When dealing with an aging UPS , there is no one right answer . Understanding the current situation and future requirements will largely determine whether it makes more sense to ‘ run to fail ’, upgrade , or buy new .

48 | February 2017