About the UR-RHV
The “V” in the order code for the UR-RHV indicates that this module is intended for the vertical mount version of the Universal Relay series. The vertical mount units are reduced in size and intended for users with limited available space in their power system. Prospective buyers should ensure they are purchasing the module appropriate for their unit (horizontal or vertical) as there is a distinct difference between the two versions of the modules.
The Universal Relays series power supply modules have a redundant option which includes two power supplies placed in parallel with one another; if there is a fault in one of the power supplies, the other can take on the full load of the power system. This switchover happens instantly and results in zero downtime for the power system. The LEDs located on the front of the faceplate will also indicate when this failure occurs so that users can get the one power supply up and running while the other continues to take on the labor.
While some of the modules are not inherently necessary for relay function, the power supply module (along with the CPU module) is required for operation, as the relay cannot run without a connected source.