UPS Systems

Types

• Offline (standby) UPS — switches to battery when power fails. Basic protection for single home or small-office computers.
• Line-interactive UPS — adds voltage correction, so it handles brownouts without using the battery. Common for office computers and networking.
• Online (double-conversion) UPS — continuously supplies clean power from the inverter, with zero transfer time. Choose it for servers, labs and sensitive equipment.
• Rack-mount UPS — fits in a server rack.
• Three-phase UPS — for larger loads such as data rooms, buildings and industrial equipment.

What to check before buying

• Capacity in VA or kVA, and the power factor, because real watts equal VA multiplied by power factor.
• Backup time needed at your actual load, which determines battery capacity and whether external battery banks are required.
• Battery type (sealed maintenance-free or lithium-ion) and replacement cycle.
• Input voltage range, which matters where supply fluctuates widely.
• Output waveform: pure sine wave is preferred for electronic equipment.
• Warranty on the UPS and the batteries separately, on-site service, AMC, GST invoice and OEM authorisation.

Common brands include APC, Luminous, Microtek, Numeric and Delta.

Who buys them

Offices, server rooms, banks, hospitals, labs, schools, CCTV control rooms, factories and shops with billing computers.

Frequently asked questions

What UPS capacity does a desktop need?

A typical office desktop with a monitor draws roughly 150 to 300 watts. Add up all connected devices and choose a UPS rated comfortably above that load.

How long will the battery last?

That depends on the battery capacity and your load. Tell the supplier the load and the backup time you want, so they can specify the battery bank.

Do I need online UPS for CCTV?

A line-interactive UPS is usually enough for a small system. Choose online UPS for large recorders or where power is unstable.