White-Rodgers S84A-410 Transformer

The White-Rodgers S84A-410 is a heavy-duty, plate-mounted Class 2 energy limiting transformer designed for reliable power distribution in industrial heating and air conditioning control circuits. Engineered to step down 120V AC primary voltage to a consistent 24V secondary output, this 40VA rated component is a standard for technicians requiring a robust interface between line voltage and low-voltage control systems. Its recessed plate design provides a clean, flush-mount installation, while the 10-inch primary color-coded leads and secondary screw terminals streamline field wiring. The internal energy limiting design is specifically built to withstand momentary short circuits safely. In the event of a sustained secondary bridge, the primary winding is engineered to open within two minutes, preventing fire hazards and protecting sensitive downstream controls. With a maximum ambient operating temperature of 150°F, this 40VA HVAC transformer maintains thermal stability even in demanding mechanical room environments, ensuring long-term performance and UL Listed compliance for professional contractor installations.

• Fail-Safe Protection: The energy-limiting architecture prevents catastrophic failure by opening the primary winding during continuous secondary shorts.
• Contractor-Grade Mounting: Integrated 4x4 recessed plate allows for direct mounting to standard electrical boxes, providing a professional, finished look.
• High-Temperature Resilience: Rated for ambient conditions up to 150°F, making it suitable for high-heat attic and boiler room applications.
• Simplified Field Service: Features 10" primary wire leads and heavy-duty screw terminals on the secondary side for secure, vibration-resistant connections.

• Can I use this transformer to replace a 20VA or 30VA unit? Yes, you can always go up in VA rating (power capacity) but never down. This 40VA unit provides more headroom for additional relays or zone valves.
• Does this unit have a built-in circuit breaker? No, it utilizes an inherent energy-limiting design that opens the winding under fault conditions rather than a resettable manual breaker.
• What is the proper secondary voltage reading? While rated for 24V, a common secondary reading with no load may measure closer to 25V or 27V; this is standard for step-down control transformers.

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.