A CCTV system is not protected from load shedding because the cameras still have lights on them.
The useful system is the complete recording path: camera, local power or PoE, network switches, recorder, storage, router where remote alerts matter and the screen or workstation used to verify recovery. Break one critical link and a row of powered cameras can produce no stored evidence.
At a large KwaZulu-Natal industrial site, the documented failure was blunt. The standby generators did not start during an outage and the CCTV recorders shut down. That does not prove a particular UPS would have solved every part of that site. It demonstrates the dependency that often receives the least attention: the recorder must survive the gap between mains failure and reliable standby power—or shut down and recover in a controlled, verified way.
Draw the recording chain before buying a UPS
List every device required to fulfil the purpose.
For an IP system that may include:
- cameras;
- PoE switches, including remote switches in outbuildings;
- wireless links or fibre converters;
- the NVR or recording server;
- hard drives and external storage;
- the router, firewall and internet equipment;
- a monitor or client workstation; and
- any alarm input, notification or health-monitoring service.
An analogue or HDCVI system replaces some network components with camera power supplies and coaxial paths, but the dependency question is unchanged.
Now mark what must remain alive. A local recorder can continue recording without the internet, so backing up the router may be unnecessary for evidence but essential for remote alerts. A display can be allowed to switch off if nobody needs live viewing, saving runtime. A remote PoE switch cannot be omitted if its cameras are essential.
Generator backup and UPS backup do different jobs
A generator is generally intended to carry a substantial load for a longer period. It takes time to detect failure, start, stabilise and transfer. It can also fail to start, run out of fuel or be isolated for maintenance.
A UPS bridges interruption immediately. It can filter some power disturbances and give equipment time either to remain operational until the generator takes over or to shut down safely. Its runtime is finite, its batteries age and its inverter has limits.
They should be designed as layers, not assumptions about one another. “The building has a generator” is not a CCTV resilience specification. The questions are how long transfer takes, what happens if start fails, which distribution board supplies the CCTV circuit, and how staff know the backup did not work.
Size against measured load, not camera count
Eight cameras do not equal a fixed number of watts. Camera consumption changes when IR or white lights switch on, heaters operate, motors move or radios transmit. PoE switches consume power themselves and have both a total PoE budget and an upstream electrical draw. Recorders vary with drive count, processing and attached peripherals.
A defensible process is:
- inventory every protected device and power supply;
- record nameplate and manufacturer maximums;
- measure real operating load where possible, including night mode;
- allow headroom for starting, conversion losses and future additions;
- choose required bridge/runtime duration;
- check both watt and VA limits; and
- test the actual assembled system.
A runtime estimate printed on a box is not a commissioned result. Battery condition, temperature, load and power factor change it.
The shutdown can damage more than availability
Modern recorders are embedded computers writing continuously to disk. Sudden loss does not guarantee corruption, but repeated uncontrolled outages are not a healthy operating mode. The greater certainty is simpler: while the recorder is off, it records nothing.
Recovery also needs testing. Some equipment returns automatically; some waits for a button press; some network links recover in the wrong order and remain disconnected. The recorder may boot before a switch or storage target and not resume exactly as expected.
After power returns, verify:
- correct date and time;
- every required camera online;
- recording active on every channel;
- hard-drive health;
- event rules and schedules still enabled;
- remote access and notifications restored; and
- footage can be played from before and after the outage.
Seeing live video proves only that live video works now.
Test failure, not only normal transfer
Commissioning should include controlled scenarios agreed with the client and electrical team:
- mains removed and UPS carrying the load;
- generator starting and transfer completing;
- generator deliberately unavailable while UPS runtime is observed;
- return to mains;
- router/internet restoring after the recorder; and
- an alert or escalation when runtime is nearly exhausted.
Do not create a dangerous electrical test casually. Generator and distribution testing belongs with competent electrical personnel. The CCTV technician’s job is to verify system behaviour at each stage and document the result.
Battery maintenance is part of CCTV maintenance
UPS batteries are consumables. A green light does not prove capacity. A unit can sit happily on mains for years and collapse seconds into the first serious outage.
Record installation dates, run scheduled load tests, keep ventilation clear and replace batteries on condition and manufacturer guidance. Where the system is large, monitor the UPS and generator state rather than waiting for a guard to notice blank screens.
Practical priorities for Durban homes and small businesses
Begin with the recorder and the device that powers its cameras. Add the router if remote visibility or push notifications are important. Leave nonessential large displays off backup unless live monitoring is required.
For distributed properties, inspect every switch. Backing up the rack while an unprotected garage switch dies still loses the garage cameras. For Wi-Fi cameras, backing up the camera power but not the access point creates the same split.
The correct outcome is not “everything stays on forever.” It is a documented period during which the essential recording path remains intact, followed by an alerted and understood failure mode. Durban’s power environment makes that a core part of CCTV design, not an optional accessory at the bottom of a quote.