Will my CCTV keep recording during a power cut in Mumbai?

By default, no. Unless somebody specified otherwise, a mains outage stops the cameras, stops the recorder, and leaves a hole in your footage exactly as long as the cut — which in much of the Mumbai belt is not a rare event.

Worse, an outage is not a random inconvenience. It correlates with the conditions under which incidents happen, and it can be induced deliberately.

The chain is only as strong as its unprotected link

Recording during an outage requires every element in the chain to stay powered: the cameras, the recorder, the network switch if the cameras are IP, and the router if you need remote viewing. Protecting some of them achieves nothing.

The commonest half-measure we find is a UPS on the recorder alone. The recorder stays up, writing perfectly — black frames, because the cameras it is recording have no power. The system looks protected on paper and produces nothing.

What backup has to cover

• The recorder, including its hard disk. An abrupt loss of power mid-write is also the fastest way to corrupt a disk, so backup protects the hardware as well as the footage.
• Every camera, which for analogue systems means the power supply distributing to them, and for IP systems usually means the switch supplying power over the network cable.
• The network switch, if there is one between cameras and recorder. Easy to forget, in a cabinet nobody opens.
• The router, only if you need to view remotely during the outage. Local recording continues without it, so this is optional and worth deciding deliberately.

On an IP system with power over the network cable, this is simpler than it sounds: protect the recorder and the switch and the cameras come with them. On analogue, the camera power supply is a separate item that has to be on the UPS too.

How long is long enough

Work from your actual outage pattern rather than a round number.

• Short, frequent cuts — the common case in most residential areas. Fifteen to thirty minutes of runtime covers the majority and prevents the disk-corruption risk of repeated hard stops.
• Long scheduled cuts or monsoon-season outages measured in hours. This is where a UPS alone stops being the answer and the system should sit on whatever generator or inverter already backs up the building.
• A society or plant with an existing backup supply. Almost always the right answer is to put the security system on that circuit rather than buying a separate UPS. It is cheaper and it gets maintained along with everything else.

Sizing is a calculation, not a guess: total the wattage of the recorder, cameras and switch, then size the UPS for the runtime you want at that load. An installer who cannot show you that arithmetic is estimating.

The outage-related failure nobody plans for

Two things go wrong when power returns, and both are more common than the outage itself.

First, the recorder may not restart cleanly. Most modern units resume automatically, but a unit whose auto-restart setting was never checked can sit powered but idle for weeks. Nothing indicates this except the absence of footage.

Second, the clock. A recorder that loses its time reference on restart may resume with a wrong date, which makes footage very hard to line up with an incident and easy to challenge if it is ever relied upon. Time synchronisation is a setting, and it is worth confirming at handover.

Both are why the check after an outage matters as much as the backup during it: play back a clip from the hour after power returned, and look at the timestamp on it.

What to specify

Put these on the quote rather than assuming them:

• Which components are on backup — recorder, cameras, switch, router — listed individually
• Runtime in minutes at the actual system load, with the load stated
• Whether the recorder is set to auto-restart and re-sync its clock on power return
• Whether the UPS battery is covered by the AMC, and when it is due for replacement

That last point catches people out years later. A UPS battery has a service life of a few years and fails quietly, so a system that was genuinely protected at handover may not be now.