Functional Devices-RIB TR20VA003 Transformer

The Functional Devices RIB TR20VA003 is a 24VAC to 24VAC isolation transformer designed for professionals requiring a robust 20VA control transformer for building automation and HVACR systems. This Class 2 transformer serves as a reliable power supply for driving relays, powering sensors, and supporting digital I/O circuits in demanding environments. Featuring a foot and single threaded hub mount, it provides versatile installation options, whether you are mounting directly to a junction box or securing it within a control panel. The inherently limited overcurrent protection ensures safety without the need for external fusing, while the split-bobbin construction enhances electrical isolation. With an operating temperature range of -30°F to 140°F and 8-inch color-coded wire leads, this unit is engineered for seamless HVAC system integration and consistent voltage regulation. This 24 volt control power transformer is an essential component for technicians managing low-voltage temperature control systems and magnetic switches.

• Versatile Mounting: Includes both foot mount and a 0.5-inch NPT single threaded hub for flexible installation in various enclosures.
• Inherent Safety: Inherently limited design provides Class 2 protection against short circuits and overloads without additional circuit breakers.
• Industrial Strength: Split-bobbin construction provides high dielectric strength and reliable 24V separation for sensitive electronics.
• Wide Temp Range: Built to perform in extreme conditions from -30°F to 140°F, ideal for unconditioned mechanical rooms.
• Contractor Friendly: Pre-stripped 8-inch color-coded leads simplify field wiring and reduce labor time.

Can I use the RIB TR20VA003 for residential thermostats?
Yes, its 24VAC secondary and 20VA rating make it highly effective for powering thermostats, though you must ensure the total load of all connected devices (valves, relays, etc.) does not exceed 20VA.

Does this unit require a secondary fuse?
No. This is an inherently limited transformer, meaning it is designed to limit output current safely during a fault, meeting UL 1585 Class 2 requirements without external overcurrent protection.

What is the primary application for an isolation transformer with the same input and output voltage?
Technicians primarily use the TR20VA003 to isolate control circuits from the main power source, preventing ground loops and protecting sensitive controllers from noise or transients on the primary 24V line.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.