Power Protection Devices

Category overview

Power problems show up as everything from a flickering monitor to a corrupted database. The two main devices in this group address different parts of the problem: a UPS keeps equipment running through outages, sags and spikes; a PDU organizes how power reaches each device in a rack and how it is monitored.

What this category covers

UPS units in offline, line-interactive and online double-conversion topologies; PDUs in basic, metered, monitored and switched configurations; rack-mount and desktop form factors; and the cables and accessories that go with them.

Who this category is for

IT teams responsible for office workstations, server rooms and small data centers; anyone running equipment that should not lose data or downtime when the mains supply hiccups.

How to choose power protection

Identify the actual risks

Short outages and noisy mains are common in many sites. A UPS handles both. Power distribution and remote outlet control in a rack are different problems and need a PDU. Many sites need both, but the right capacity for each depends on what is connected.

Size by load and runtime

For a UPS, add the running power of the connected equipment in watts (not VA), then choose a unit that can hold that load for the time it takes to either shut down cleanly or for a generator to take over. For a PDU, count the connected outlets and the per-outlet current, plus the total feed.

Decide on management features

Network-managed UPS units and switched PDUs allow remote monitoring, scheduled reboots and per-outlet control. For unattended sites, this is often essential. For a single office UPS under a desk, a simple unit with USB management is usually enough.

What to check before buying

• What is the total wattage of the equipment to protect, including future additions?
• How long does the runtime need to be: brief sag protection, shutdown time, or full ride-through to a generator?
• Is remote management or alerting required?
• Does the rack have the right depth and outlets for a metered or switched PDU?
• Are the input and output connectors correct for the country and equipment?

Frequently asked questions

What is the difference between a UPS and a PDU?

A UPS provides backup power and conditioning so equipment stays online during outages and disturbances. A PDU distributes power from a feed to multiple outlets, often with monitoring and remote switching. The two are complementary: a UPS often feeds a PDU, which then feeds individual servers.

How long should a UPS keep my equipment running?

Long enough to ride through the typical outage, or to shut the equipment down cleanly. For office PCs, 5 to 10 minutes is usually sufficient with automatic shutdown configured. For sites with a backup generator, the UPS only has to bridge the few seconds until the generator is online.

Do I need a switched PDU or will a basic one do?

A basic PDU just distributes power. A switched PDU lets each outlet be turned on or off remotely, which is essential for unattended sites where rebooting a hung server should not require an on-site visit. Metered PDUs without switching report current draw but cannot cut individual outlets.

Will a surge strip do the job of a UPS?

No. A surge strip only handles brief spikes and does nothing for outages, sags or extended undervoltage. A UPS includes surge protection and adds battery backup with conditioning, which is what equipment with stored data actually needs.

How often should UPS batteries be replaced?

Lead-acid UPS batteries typically need replacement every three to five years; lithium-ion batteries last longer. Most managed UPS units report battery health and warn before failure. Replacing on schedule is much cheaper than discovering the failure during an outage.