There are two concerns that you have to be aware of when you are evaluating RPS solutions for fixed Cisco catalyst switches. Cisco has a product named Cisco Redundant Power System 2300 (RPS 2300) for the non-modular switch series like Catalyst 3560, Catalyst 3750. It is the successor of the old Cisco Redundant Power System 675 (RPS 675).
You have only one bullet in your gun when you have an RPS
You can provide a limited redundancy to your network by installing an RPS for your Catalyst Switches. Switch survives without rebooting when the main power cut off. It draws power from RPS but never returns to the main power. An orange LED indicates the switch powered by RPS. If you press the standby/active button on the RPS, your switch will reboot and become a regular operation. The only exception is the E series switches + RPS 2300 combination. This combination can restore the power state without rebooting.
RPS supports only one switch (two in some cases) at a time
You can attach up to 6 switches to the RPS, but if power Circuit 1 fails as shown in the scenario above, RPS can only support one switch, and the rest will fail. If the power requirements are moderate, the RPS 2300 can support up to two switches but not more.