Resideo RC840T-120 Electromechanical Relay
The Resideo RC840T-120 Electromechanical Relay with a built-in 24V transformer is a critical component for integrating line-voltage equipment into low-voltage control systems. This switching relay operates on a 120 Vac input and provides a 24V, 40 mA, 1.2 VA control signal, making it the industry standard for controlling electric baseboard heaters, resistive cooling loads, and inductive fan motors. The unit features an internal transformer that simplifies field installations by eliminating the need for an external power source when interfacing with 24V 2-wire or 3-wire thermostats. Designed for high-reliability on/off switching, it maintains a robust temperature rating of -4°F to 140°F, ensuring stable performance in unconditioned mechanical spaces. For technicians, this 120V to 24V relay is essential for retrofitting older line-voltage systems with modern digital thermostats, providing a seamless bridge for HVAC line-voltage control without compromising circuit integrity.
Key Benefits for Contractors- Integrated 24V Transformer: Eliminates the need for additional power supplies, saving space in the junction box and reducing installation time.
- Broad Compatibility: Fully supports 2-wire and 3-wire 24V thermostats, allowing for versatile control over electric heat or fans.
- High Current Capacity: Rated for up to 22A resistive loads at 120V, suitable for high-wattage heating applications.
- Silent Operation: The electromechanical design ensures reliable switching with minimal acoustic noise, ideal for residential zones.
- Compact Enclosure: Easily mounts to standard 4x4 electrical boxes for a clean, professional finish.
Can I use this relay with a 3-wire smart thermostat?
Yes, the RC840T-120 provides a 24V AC signal compatible with 3-wire thermostats, though you must verify the VA draw of your specific thermostat does not exceed the 1.2 VA signal rating.
Is this unit suitable for inductive fan loads?
Yes, while commonly used for resistive heating, this electromechanical relay is rated for inductive loads such as fans and motors common in HVACR applications.
What is the proper mounting orientation for the RC840T-120?
It is typically mounted directly to a junction box. Ensure the ambient temperature remains within the -4°F to 140°F range for optimal contact longevity.
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.
Original: $76.10
-65%$76.10
$26.63Resideo RC840T-120 Electromechanical Relay
The Resideo RC840T-120 Electromechanical Relay with a built-in 24V transformer is a critical component for integrating line-voltage equipment into low-voltage control systems. This switching relay operates on a 120 Vac input and provides a 24V, 40 mA, 1.2 VA control signal, making it the industry standard for controlling electric baseboard heaters, resistive cooling loads, and inductive fan motors. The unit features an internal transformer that simplifies field installations by eliminating the need for an external power source when interfacing with 24V 2-wire or 3-wire thermostats. Designed for high-reliability on/off switching, it maintains a robust temperature rating of -4°F to 140°F, ensuring stable performance in unconditioned mechanical spaces. For technicians, this 120V to 24V relay is essential for retrofitting older line-voltage systems with modern digital thermostats, providing a seamless bridge for HVAC line-voltage control without compromising circuit integrity.
Key Benefits for Contractors- Integrated 24V Transformer: Eliminates the need for additional power supplies, saving space in the junction box and reducing installation time.
- Broad Compatibility: Fully supports 2-wire and 3-wire 24V thermostats, allowing for versatile control over electric heat or fans.
- High Current Capacity: Rated for up to 22A resistive loads at 120V, suitable for high-wattage heating applications.
- Silent Operation: The electromechanical design ensures reliable switching with minimal acoustic noise, ideal for residential zones.
- Compact Enclosure: Easily mounts to standard 4x4 electrical boxes for a clean, professional finish.
Can I use this relay with a 3-wire smart thermostat?
Yes, the RC840T-120 provides a 24V AC signal compatible with 3-wire thermostats, though you must verify the VA draw of your specific thermostat does not exceed the 1.2 VA signal rating.
Is this unit suitable for inductive fan loads?
Yes, while commonly used for resistive heating, this electromechanical relay is rated for inductive loads such as fans and motors common in HVACR applications.
What is the proper mounting orientation for the RC840T-120?
It is typically mounted directly to a junction box. Ensure the ambient temperature remains within the -4°F to 140°F range for optimal contact longevity.
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.
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Description
The Resideo RC840T-120 Electromechanical Relay with a built-in 24V transformer is a critical component for integrating line-voltage equipment into low-voltage control systems. This switching relay operates on a 120 Vac input and provides a 24V, 40 mA, 1.2 VA control signal, making it the industry standard for controlling electric baseboard heaters, resistive cooling loads, and inductive fan motors. The unit features an internal transformer that simplifies field installations by eliminating the need for an external power source when interfacing with 24V 2-wire or 3-wire thermostats. Designed for high-reliability on/off switching, it maintains a robust temperature rating of -4°F to 140°F, ensuring stable performance in unconditioned mechanical spaces. For technicians, this 120V to 24V relay is essential for retrofitting older line-voltage systems with modern digital thermostats, providing a seamless bridge for HVAC line-voltage control without compromising circuit integrity.
Key Benefits for Contractors- Integrated 24V Transformer: Eliminates the need for additional power supplies, saving space in the junction box and reducing installation time.
- Broad Compatibility: Fully supports 2-wire and 3-wire 24V thermostats, allowing for versatile control over electric heat or fans.
- High Current Capacity: Rated for up to 22A resistive loads at 120V, suitable for high-wattage heating applications.
- Silent Operation: The electromechanical design ensures reliable switching with minimal acoustic noise, ideal for residential zones.
- Compact Enclosure: Easily mounts to standard 4x4 electrical boxes for a clean, professional finish.
Can I use this relay with a 3-wire smart thermostat?
Yes, the RC840T-120 provides a 24V AC signal compatible with 3-wire thermostats, though you must verify the VA draw of your specific thermostat does not exceed the 1.2 VA signal rating.
Is this unit suitable for inductive fan loads?
Yes, while commonly used for resistive heating, this electromechanical relay is rated for inductive loads such as fans and motors common in HVACR applications.
What is the proper mounting orientation for the RC840T-120?
It is typically mounted directly to a junction box. Ensure the ambient temperature remains within the -4°F to 140°F range for optimal contact longevity.
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.
