Question 1

What VA rating UPS do I need for a CCTV system?

Accepted Answer

Add up the wattage of all devices — NVR, cameras, PoE switch, monitors — and divide by 0.8 to get the minimum VA rating. A 300W total load requires at least a 375VA UPS. Size the UPS 20–25% above the calculated minimum to allow headroom for startup surges and future load additions.

Question 2

How long will a UPS run a CCTV system?

Accepted Answer

Runtime depends on the battery bank capacity (Ah), the total load in watts, and the efficiency of the system. This calculator sizes the battery bank for a target runtime you specify — set your required backup duration (hours and minutes) and the tool returns the Ah capacity needed at the chosen battery voltage.

Question 3

Should I use a 12V or 24V battery for a security system UPS?

Accepted Answer

For small systems (one NVR, a few cameras, under 150W), a single 12V battery is usually sufficient. For larger installations, a 24V bank (two 12V batteries in series) gives more capacity in a manageable form factor and reduces current, lowering cable and connector losses. The battery voltage does not change the total energy output — only the amp-hour figure changes.

Question 4

Can I use a standard office UPS for CCTV?

Accepted Answer

Yes, for short runtimes. Standard office UPS units (typically 5–15 minutes at full load) are adequate for graceful shutdown protection. For security applications requiring 2–8 hours of backup, you need a UPS with an external battery connection or a dedicated DC power backup unit sized using the calculations above.

calculators.ups.load.thName	calculators.ups.load.thQty	calculators.ups.load.thPower
storage 16ch NVR Recorder		W
storage IP Camera		W
storage PoE Switch		W
storage Monitor		W
add_circle		W
calculators.ups.load.totalPower		320W

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