Building automation system (BAS) retrofits in California are shaped by the 2025 Title 24 energy code, which can reach existing buildings when an alteration triggers mechanical, lighting, or envelope compliance. Much of the state's commercial stock, across office towers, healthcare facilities, schools, and retail in Los Angeles, the Bay Area, San Diego, and Sacramento, predates 2010, so retrofit and equipment-replacement work is a large share of the controls market.
RIB® (Relay-In-a-Box®) relays, wireless EnOcean devices, current sensors, and prepackaged power supplies from Functional Devices, Inc. give California BAS contractors a hardware layer for modernizing these systems without full replacement.
When Title 24 Applies to a Retrofit
Title 24 is most commonly associated with new construction, but alterations that touch mechanical, lighting, or envelope systems often pull the affected scope into the current cycle, including acceptance testing of the modified controls. That makes equipment replacements and control upgrades a common point where the 2025 code can affect an older building.
Wired RIB® Relay Integration
For retrofit points where control wiring can be run cost-effectively, an enclosed RIB® relay provides a UL Listed switching point that integrates with any new BAS controller. The new controller's binary output connects to the relay coil; the contacts switch the legacy load, with complete electrical isolation between the new low-voltage controller and the existing line-voltage circuit. The RIB2401B (20A SPDT, 24 VAC/DC or 120 VAC coil) is the standard choice for most wired retrofit switching points, from fan coil units to rooftop unit enable circuits.
Retrofit panels also need 24V control power for the new controllers and sensors. RIB® prepackaged power supplies deliver it in a prewired enclosure with transformer and breaker included, with no field assembly and no separately sourced components.
Wireless RIB® Relay Integration
Where running new control wire is cost-prohibitive, through finished ceilings, across large floor plates, or in occupied healthcare and educational facilities, EnOcean-enabled wireless RIB® relays remove the wiring requirement. The RIBW24B-EN3 is a 20A SPDT EnOcean wireless relay transceiver with 24 VAC power input that mounts at the load and pairs with self-powered EnOcean occupancy sensors and switches. In a California school district retrofit, wireless relays and occupancy sensors can add classroom-level occupancy-based HVAC control without opening walls during the school year.
Current Sensor Instrumentation for Retrofit BAS Systems
Adding split-core RIB® current sensors gives a retrofit BAS real-time feedback on whether equipment is running, not just whether it was commanded on. Fan proving, compressor monitoring, and run-hour tracking become possible without modifying existing wiring.
The RIBXGTA is a split-core adjustable current switch with a 0.75–150A sensing range and dry contact output that interfaces directly with BAS binary inputs, which also supports Title 24 acceptance documentation and load management against CAISO demand charges. For the variable-speed ECM and VFD-driven equipment increasingly common in California retrofits, a low-threshold sensor reads the small, variable draws a standard current switch would miss.
Frequently Asked Questions
Does a control retrofit trigger Title 24 in California?
It can. Alterations involving mechanical, lighting, or envelope work often require the affected scope to meet the current Title 24 cycle, including acceptance testing. Confirm the trigger with the local building department for the specific project.
Can I retrofit BAS controls without running new wire?
EnOcean wireless devices avoid new low-voltage wiring, which is the main reason they are used in occupied or finished buildings. Wired RIB® relays remain the choice where conduit access is straightforward.
Source RIB® Relays for California BAS Retrofits
For a California BAS retrofit, the wired and wireless RIB® relays, current sensors, and prepackaged power supplies covered here are stocked through authorized Functional Devices distributors statewide, with local availability across Los Angeles, the Bay Area, San Diego, and Sacramento.
Sourcing the switching, instrumentation, and control power from one distributor keeps a retrofit moving without splitting the order across suppliers. Browse the RIB® relay lineup, or find an authorized Functional Devices distributor in California.