Rheem-Ruud 42-21593-02 Sequencing Relay

For service technicians managing multi-stage electric heat or residential blower delays, the Rheem-Ruud 42-21593-02 Sequencing Relay functions as a critical OEM control component. This 24V SPDT Sequencing Relay is engineered with a C65-95 timing specification, ensuring precise contact closure and opening cycles to prevent line-side surges during startup. The device features a single pole double throw configuration, allowing for versatile field wiring of both normally open and normally closed circuits. With a thermal heater wattage rating of 0.16A steady state and a 0.9A inrush, this 42-21593-02 relay operates reliably within low-voltage control loops. The flush-mount plate design, integrated with standard 1/4-inch quick-connect terminals, facilitates rapid installation in tight air handler cabinets. Built to handle motor loads up to 14 FLA at 120V, this HVAC sequencer maintains system stability by staggering electrical loads, protecting the integrity of the heat strip assembly and minimizing mechanical stress on the blower motor.

• OEM Precision: Direct replacement for Rheem and Ruud air handlers, ensuring factory-spec timing for staged heating elements.
• Optimized Sequencing: The C65-95 rating provides a 65 to 95-second off-delay, preventing simultaneous power draw across high-amperage components.
• Durable Construction: Heavy-duty SPDT switching contacts rated for 125 VA pilot duty, capable of handling inductive and resistive loads.
• Universal Mounting: Includes a standard flush-mount plate with universal hole and tab configurations for compatibility with various bracket styles.

What does the C65-95 rating signify for this relay?
This rating indicates the factory-set delay timing. The relay typically engages the first stage between 1 and 60 seconds and ensures the circuit breaks between 65 and 95 seconds after the control signal is removed, preventing rapid cycling.

Is the 42-21593-02 compatible with 240V fan motors?
While the control heater operates on 24VAC, the contacts are rated for power circuits. It can handle up to 7 FLA at 230V/240V for motor loads, making it suitable for standard residential blower applications.

Can this SPDT relay replace a standard SPST sequencer?
Yes, if your application requires a single load switch, the SPDT configuration allows you to use the normally open terminals while leaving the normally closed terminal unused, providing greater flexibility for field modifications.

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.