Uninterruptible power supplies

An uninterruptible power supply (UPS), is a large battery that ensures clean, continuous power for any device plugged into it. Also known as a battery backup, an uninterruptible power supply is similar to a surge protector. But it provides significantly more protection and is commonly required for IT assets and critical equipment.

While surge protectors only shield against electrical surges, the UPS protects against surges, under voltages, and other types of electrical noise. The UPS plugs into a wall outlet and contains additional outlets similar to a surge protector. But unlike a surge protector, the UPS also contains a battery. When the UPS detects adverse power conditions — like if a storm causes a power outage — it switches to battery power instantly. Switching to battery power protects critical assets such as a video intercom.


There are three types of uninterruptible power supplies:

  1. Offline/Standby
  2. Online/Double Conversion
  3. Line-Interactive



Offline/Standby UPS usually gets its power from an AC outlet and provides both battery backup and light surge protection. When the main power source fails, it switches to the ‘offline/ standby’ battery where it then goes to the DC/AC inverter.


Online/Double Conversion

The main difference between the online/double conversion and the offline/standby is transfer time.

In the online/double conversion, the DC/AC converter is always on, meaning there is no transfer time between the main power source and the battery. In contrast, the offline/standby has a short transfer time because it’s in ‘standby’ mode. This means that the online/double conversion offers greater surge protection.



A line-interactive UPS is a blend of the two – it can handle small under-voltages and over-voltages in which the battery is not being used. A line-interactive similar — design-wise — to offline/standby. But just like the online/double conversion, there is no switching time from the power source to the inverter.


Uninterruptible power supplies for ButterflyMX installations

Although we generally recommend offline/standby for the installation of ButterflyMX video intercoms, any of the three options work just fine.

But uninterruptible power supplies also come in various sizes. The correct size depends on whether the UPS is protecting something as small as a single computer or as large as an entire building.

ButterflyMX requires a UPS device for continuous, clean power, not for battery backup. We typically recommend a 330 watt APC UPS (the BE600M1). This satisfies our technical need for a UPS device, but it only provides about 10 minutes of backup time. If you would like longer battery life, it’s perfectly fine to get a larger UPS device. As long as the ButterflyMX intercom has a minimum of 300 watts of dedicated power from the battery section of the UPS, it will satisfy our requirements.


Be sure to check out our installer resources page for more information on installing our smart video intercoms.

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Meredith Murray

My passion lies at the intersection of real estate & technology. Brooklynite always.