Resideo SDCR Relay

The Resideo SDCR Relay is an essential slave damper control relay designed for professional HVAC partitioning where existing zone panel contacts aren't sufficient to handle the total inductive load. This 4PDT relay (4-pole, double-throw) lets a single zone output synchronize up to nine dampers, provided the secondary power supply is correctly sized. Built for high-density HVAC zoning systems, the SDCR effectively manages multiple damper actuators like the ARD or ZD series, reducing the risk of overloading primary control boards and ensuring consistent airflow across large zones.

For a clean field install, this unit features a finger-safe terminal strip and a compact footprint that fits inside a standard metal enclosure. When de-energized, the SDCR wiring provides 24V power across the M1 and M6 terminals to drive dampers closed; once 24V is applied to the C-C coil terminals, the relay switches power to the M1 and M4 terminals to drive the actuators open. Professionals should utilize a dedicated 24VAC, 40VA transformer to power the secondary load via terminals 1 and 2, protecting the logic of the master zoning panel while maintaining precise damper positioning.

Key Benefits

• Controls up to 4 dampers directly, or up to 9 dampers in parallel if transformer VA allows.
• Robust 4PDT switching provides high-capacity control for complex residential and commercial ductwork.
• Low-voltage 24V operation integrates seamlessly with Resideo Mastertrol and Trol-A-Temp legacy panels.
• Compact, mountable design simplifies organization within the mechanical room or air handler cabinet.
• Reduces the electrical burden on primary zone control boards to prevent premature component failure.

Common Questions

• How do I wire the SDCR to an older 5-terminal zone panel? On panels with M1-M2-M4-M5-M6 terminals, you must install a jumper between M2 and M5 on the specific zone controlling the relay.
• What type of transformer is required for the SDCR? A dedicated 24 Volt AC, 40 VA transformer is recommended to ensure enough head-room for multiple actuators, especially in high-temp environments like attics.
• Can I use this with 3-wire dampers? Yes, the SDCR supports 3-wire configurations; connect terminals M1, M4, and M6 to the corresponding damper terminals 1, 4, and 6.

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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.