Relays and Relay Capabilities (RIBU1C & RIBU2C)

There are many capabilities and functions of RIB relays. The RIBU1C and the RIBU2C are two of the most common and user-friendly relays. Using 10-30 AC/DC voltage or 120V AC voltage, these relays can control one or two legs of power. They are commonly used to break 120V and 208/230V high-voltage power sources. These relays have normally closed (N/C) and normally open (N/O) contacts that change state when voltage is applied or removed.

Power is applied to the N/C set of contacts on the RIBU1C through the yellow and blue wires, with yellow serving as common and blue as N/C. The N/O set of contacts is controlled by the yellow and orange wires, with yellow as common and orange as N/O. If you have a RIBU2C, it contains two relays instead of one. The wire colors for the N/C and N/O sets of contacts for the first relay are the same as those of the RIBU1C, but they differ for the second relay. For relay two, the N/C set of contacts is controlled by the purple and gray wires, with purple as common and gray as N/C. The N/O set of contacts for relay two is controlled by the purple and brown wires, with purple as common and brown as N/O.

These relays are a simple solution for interlocking external pieces of equipment with various HVAC systems, such as interlocking a rooftop unit with a 120V exhaust fan. When the indoor fan on the rooftop unit is energized, the contacts on the RIB relay close, activating the exhaust fan. By utilizing C and R on the rooftop control board with the Wht/Yell and Wht/Blu wires on the RIB relay, along with the yellow and orange wires to break 120V for the exhaust fan using the N/O contacts, this process can be achieved effectively.

These relays are suitable for both commercial and residential applications. They are widely available at most major HVAC suppliers and are quick and easy to install.