Functional Devices
Functional Devices TR100VA002 Transformer 100VA 120V-24V Dual Hub Class 2 with Circuit Breaker
Functional Devices Enclosed Time Delay Relay SPDT Class Dry Contact Relays & Fan Sequencers
Functional Devices MHP3904100AB10 Single 100 VA Power Supply with 12.5" x 24.5" x 6.5" Metal Enclosure
Functional Devices RIBM24S Enclosed Relay 15A SPST 24VAC/DC Track Mount with Override
Functional Devices RIBHX24BA Enclosed Relay 20A SPST N/O with Adjustable Current Sensor
Functional Devices RIBD2421C SPDT Enclosed Pilot Relay 10 Amp with Timer 24VAC/DC 120-277VAC Coil
Functional Devices PSMN500A Power Supply 120/240/277/480V to 24VAC Modular Multi-Tap UL Class II
Functional Devices RIB2421SB Enclosed Relay 20 Amp SPDT with Override 24Vac/dc
Functional Devices RIB2402SB Enclosed Power Relay 20 Amp SPST-N/O with Override 24VAC/DC 208-277VAC
Functional Devices RIB2402B2G Power Relay 20 Amp DPDT 24 Vac/dc 208-277 Vac Coil NEMA 1
Functional Devices RIB2401SB 20 Amp SPST-NO Enclosed Relay with Override 24VAC/DC/120VAC
Functional Devices RIB2401D-N4 Enclosed Relay NEMA 4/4X 10 Amp DPDT 24Vac/dc/120Vac
Functional Devices RIB2401C Enclosed Pilot Relay 10 Amp SPDT TriVolt 24VAC/DC/120VAC NEMA 1
Functional Devices RIB2401B2G Enclosed Relay 20 Amp DPDT 24VAC/DC/120VAC Coil
Functional Devices RIB02SBDC Enclosed Relay 20 Amp SPST with Override 208-277VAC
About Functional Devices
Functional Devices has built a strong reputation as a leading American designer and manufacturer of control devices for the HVAC, building controls, and energy management industries. Founded on the principle that reliable, precision-engineered components are the backbone of any well-functioning building system, Functional Devices has become a go-to name for contractors, engineers, and facilities managers who demand consistency and quality from their electrical control hardware.
What sets Functional Devices apart is their commitment to domestic manufacturing. Every product is designed and built in the United States, ensuring tight quality control and shorter lead times compared to overseas alternatives. Their catalog of over 200 products covers the critical electrical and control components that keep commercial and residential HVAC systems running safely and efficiently.
Transformers for HVAC and Building Controls
One of Functional Devices' most recognized product lines is their lineup of Transformers. These step-down control transformers are engineered specifically for HVAC applications, converting line voltage down to the 24VAC signal voltage that thermostats, zone valves, and control boards depend on. Functional Devices transformers are designed with built-in overcurrent protection and a range of VA ratings to match virtually any residential or commercial application.
Relays, Fan Sequencers & Automation Controls
Perhaps the product line Functional Devices is best known for is their Relays & Fan Sequencers. Their iconic RIB® (Relay in a Box) series revolutionized the industry by packaging a fully enclosed, plug-in relay into a compact, universal-mount enclosure — eliminating the need for a separate panel or DIN rail in many installations. Fan sequencers from Functional Devices help stage multi-speed blower motors and electric heating elements efficiently, reducing electrical stress and improving system longevity.
Motor & Electrical Parts and Accessories
Beyond their flagship lines, Functional Devices also offers a selection of Motor & Electrical Parts & Accessories that complement their control systems. These components are designed to integrate seamlessly with Functional Devices transformers and relays, making it straightforward to build or service a complete control circuit without sourcing parts from multiple vendors.
Accessory Power Relays
For applications requiring switched power control, Functional Devices produces Accessory Power Relays suited to a variety of load types. These relays provide dependable switching action for auxiliary equipment loads, and their robust construction reflects the same durability standards applied across the entire Functional Devices product range.
Why Choose Functional Devices?
- American-designed and manufactured for consistent quality and reliability
- Extensive product range covering transformers, relays, sequencers, and accessories
- Industry-leading RIB® relay platform with universal mounting flexibility
- Products engineered specifically for HVAC, building automation, and energy management systems
- Trusted by HVAC contractors, electrical engineers, and facilities professionals nationwide