A multi-building BAS retrofit requires specifying control points across buildings that rarely share the same legacy controls, voltages, or loads. RIB® (Relay-In-a-Box®) relays from Functional Devices, Inc. can be used for most of these control points, paring down the number of necessary parts, reducing risk of error, and simplifying the installation process overall.
A Multi-Building Retrofit’s Relay Count
Control points differ in two ways that drive relay selection: the control voltage that operates the relay, and the load it switches. One building’s controller might output 24 Vac, another’s 24 Vdc, an older one 120 Vac. Loads run from a fan coil to a rooftop unit to a lighting contactor. If you have to spec a voltage-specific, load-specific relay for each combination, the SKU list will run incredibly long. On top of that, the longer that list, the greater the risk of installation error.
Standardize on a Universal-Input Relay
The RIBU1C has a coil that accepts 10–30 Vac/dc or 120 Vac, so one relay can operate from a 24 Vac output in one building, a 24 Vdc output in another, and a 120 Vac circuit in a third. Its 10 Amp SPDT contacts handle the light-duty switching most control points need: fan coil control, small lighting loads, solenoid coils. Across a multi-building installation—a campus, for example—that one relay can cover the majority of control points, simplifying things significantly.
A few control points fall outside the RIBU1C’s range of ability.
Higher-Current Loads: For a load greater than 10 Amps, the RIB2401B is a 20 Amp SPDT relay with a 24 Vac/dc or 120 Vac coil.
Two Circuits or a Contactor: For a control point that needs two independent circuits, or has to pilot a contactor, the RIB24P is a 20 Amp DPDT relay with a 24 Vac/dc coil and pilot-duty ratings.
Sourcing Relays for a Longer-Term Project
A multi-building retrofit can take months to complete, so the necessary parts must be continually available the whole time. Standardizing on a few RIB relays from one manufacturer means the model numbers can be kept consistent from the first building to the last, and it also lets a crew easily locate the same parts, even as the job moves site to site, from a local authorized Functional Devices distributor.
Frequently Asked Questions About a Multi-Building BAS Retrofit
How does standardizing relays reduce callbacks on a retrofit?
Fewer relay types means fewer wrong parts pulled and one wiring pattern the crew repeats in every building, which decreases the likelihood of installation errors.
Which relay is most widely applicable for a multi-building job?
The RIBU1C. Its universal 10–30 Vac/dc or 120 Vac coil operates from most control voltages, and its 10 Amp SPDT contacts handle light-duty switching, so one part covers the majority of control points across the buildings.
What if a load is more than 10 amps?
Step up to the RIB2401B, a 20 Amp SPDT relay. For two independent circuits or to pilot a contactor, use the RIB24P, a 20 Amp DPDT relay with pilot-duty ratings.
How do I confirm equipment is running after a retrofit?
Use a current switch. The RIBXGTA clamps around the motor conductor and reports current flow, so the controller can tell a running motor from one that failed.
How do I keep the same relays in stock across a long project?
Standardize on a few RIB models and source them through an authorized Functional Devices distributor, which stocks the common models and can re-supply the same parts as the job moves between sites.
Standardize Relays Across Your Retrofit
To standardize the relays across a multi-building retrofit, view the full RIB® relay line. For project volume, find an authorized Functional Devices distributor near you.