Choose an output voltage that matches the connected devices, then select a current capacity that covers their combined load with practical headroom for startup or future additions. Select the number of outputs based on how many devices need separate power connections, using multi-output models when you need individual distribution or protection for multiple circuits.

Check the specific switch-mode power supply’s input requirements, which may include 115 VAC, 115/230 VAC, 100 to 240 VAC, or a specified low-voltage AC input, along with the listed frequency and current rating. Use the provided screw terminals, terminal connectors, or plug and match the wiring to the selectable 12 or 24 VDC output, protected distribution terminals, battery connections, and device polarity shown in the product documentation.

Choose a switch-mode power supply with battery charging or backup capabilities when connected security, access control, or surveillance equipment needs to remain powered during an AC outage. Choose supervision when the installation needs monitoring for AC power, battery condition, low-voltage events, or other faults, especially in systems with multiple outputs or remotely powered devices.

Compare switch-mode power supplies for short-circuit, overload, and thermal protection, including auto-resetting PTC or self-limiting circuits that help protect connected equipment and simplify recovery. For installations with backup batteries, also consider low-battery cutoff, automatic transfer to battery during AC loss, surge protection, and AC or battery supervision.