If you’re like us, the mere thought of a blackout or power
surge makes you cringe. Resulting data loss can be devastating
and can leave you with irreparably damaged
hardware. Never fear, though: A UPS device can mitigate
your worries by delivering constant power levels to connected
equipment and maintaining appropriate voltage
in the cases of outages or surges. Whether you manage
a large group of servers or just a few desktop computers,
deploying a UPS in your infrastructure could be one
of the best (and easiest) decisions you ever make.
Before you hand your money over to a particular
vendor, you need to address several preliminary questions
within your organization. How often do power outages
or power surges occur in your area? How many
pieces of equipment do you want to protect, and what
is their total wattage? How would your company be
affected by a power loss? These questions—along with
the considerations that follow—will help you determine
the type of UPS you need.
Choose the Right Type
There are three basic types of UPSs: standby (offline),
line-interactive, and online. Although the three types are
similar in functionality, they have distinct differences.
Standby. A standby UPS uses the commercial AC line
as its primary power source, and when a power outage
or voltage drop occurs, the primary source switches
from the AC line to the UPS’s internal battery. This
switch between power sources happens quickly but isn’t
instant—it should be brief to avoid causing your equipment
to shut down. Standby is the cheapest UPS type
and is intended for equipment such as desktop computers
and fax machines.
Line-interactive. The line-interactive UPS uses an
inverter/converter, which serves two purposes: charge
the UPS’s internal battery and convert the battery’s DC
power to AC power to run your connected equipment.
The advantage of line-interactive is that the
inverter/converter is always connected to the UPS’s output,
providing a faster response time to power failure.
Although line-interactive provides better protection
than standby does, the primary power source is still the
AC line, leaving it one step behind the third type, online.
Online. An online UPS simply offers the best protection
for your equipment; it’s the only type that doesn’t
use the AC line as its primary power source. In this case,
the battery is the primary power source and constantly
supplies power to your connected equipment, eliminating any transfer time between primary and secondary
power sources. Although it’s the most expensive type
of UPS, online will give you the most protection and is
most suitable for larger, mission-critical systems, for
which power outages are unacceptable.
Output Capacity
Selecting a UPS capacity is a crucial factor in your purchase.
Vendors use volts × amperes (VA) to measure the
amount of power that the UPS will supply to your connected
equipment. For the purpose of this enterprisefocused
buyer’s guide, vendors provided data for UPSs
that offer capacities greater than or equal to 1000VA. As
a rule of thumb, you should always purchase a UPS with
a capacity of about 20 to 25 percent higher than the total
wattage of the equipment you need to protect. You also
need to factor in any future additions you might make
to your IT infrastructure: Buying a higher-capacity UPS
upfront will save you money, as opposed to purchasing
further small-capacity UPSs down the road. Many vendors
have online guides to help you make this decision,
so be sure to visit vendors’ Web sites for advice.
Rack-Mount vs. Standalone
The two basic UPS form factors are standalone and rackmountable.
Standalone refers to either a vertical or horizontal
unit that sits on the floor next to the equipment
you want to protect. Rack-mountable units, as their
name implies, fit into your existing rack space and are
probably the most logical form factor because they can
be stacked to save space. UPSs are also available in a
rack-mount/tower form factor, which lets you interchange
between rack mount and tower.
Management Concerns
The UPS device is vital to any IT infrastructure, but
before you make that final decision, determine whether
management software is included with your UPS, especially
if you’ll have multiple UPSs controlling critical
pieces of equipment. Management software can automatically
shut down your equipment and send alerts
when power concerns arise. Also, consult your vendor
about warranties and available on-site service, particularly
if you have many UPSs, because replacing the batteries
can be time consuming.
View Buyers Guide
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