Power cuts and voltage fluctuations are common in many parts of India, and they damage computers, servers, CCTV recorders and network equipment. A UPS (Uninterruptible Power Supply) protects them – but not every UPS works the same way. Here is a simple explanation from SKB IT Solutions, which supplies UPS systems and computer hardware in Gurgaon.
Offline (standby) UPS
An offline UPS passes mains power directly to your equipment and switches to battery only when power fails. The switch takes a few milliseconds.
- Good for: single desktops and home use
- Pros: low cost, compact
- Cons: no protection from voltage fluctuations, small switch-over gap, not ideal for sensitive equipment
Line-interactive UPS
A middle option that also corrects small voltage changes using an automatic voltage regulator, without switching to battery each time. Suitable for small offices and network equipment.
Online (double-conversion) UPS
An online UPS converts incoming power to DC and back to clean AC all the time. Your equipment always runs from the UPS, so there is zero switch-over time and full protection from spikes, surges and fluctuations.
- Good for: servers, NVR/DVR, network racks, medical and lab equipment, whole-office backup
- Pros: cleanest power, best protection, handles unstable supply
- Cons: higher cost, more heat and noise, needs proper installation
Comparison at a glance
| Factor | Offline | Line-interactive | Online |
|---|---|---|---|
| Switch-over time | Few ms | Few ms | Zero |
| Voltage correction | No | Basic | Full |
| Cost | Lowest | Medium | Highest |
| Best for | Single PC | Small office, routers | Servers, CCTV, critical systems |
How to size a UPS
- Add up the wattage of all equipment you want to run on backup
- Choose a UPS with about 20–30% spare capacity
- Decide the backup time you need – this sets the battery size
- For longer backup, ask about external battery banks
- Keep the UPS in a ventilated place and test batteries regularly
Tip: always connect your CCTV recorder, network switch and firewall to the UPS, so security and internet keep working during a power cut.
Frequently asked questions
How long do UPS batteries last?
Typically 2–4 years depending on usage, temperature and power-cut frequency. Regular checks help replace them before they fail.
Can I run my whole office on one UPS?
Yes, with a correctly sized online UPS and battery bank. Many offices use one central UPS for computers and network equipment and keep ACs on the generator.
Is an inverter the same as a UPS?
No. A home inverter has a longer switch-over time and less clean output. Computers, servers and network gear are better protected by a proper UPS.
Need help choosing the right UPS for your office? Contact SKB IT Solutions or call/WhatsApp +91-9717575348.