System Sensor R-24T 4-Gang DPDT Relay with Tamper

System Sensor R-24T 4-Gang DPDT Relay Module with Tamper Protection

Overview

The System Sensor R-24T is a 4-gang DPDT (Double Pole Double Throw) relay module designed for fire alarm system integration and control applications. This relay module provides independent switching capability across four relay banks, enabling coordinated activation of auxiliary equipment, notification appliances, and building system interfaces. The R-24T integrates seamlessly into System Sensor fire alarm control panels and compatible third-party systems requiring hardwired relay control outputs.

Key Features

• 4-Gang DPDT Configuration: Four independent relay banks, each capable of switching 24 VDC or 120 VAC loads at rated capacity, providing flexible control for multiple system zones or functions
• Tamper Protection: Built-in tamper detection circuit alerts the control panel to unauthorized module removal or wiring tampering, maintaining system integrity
• Hardwired Integration: Connects directly to System Sensor control panel relay output terminals with standard screw-terminal connections for reliable, maintenance-free operation
• Dual Voltage Compatibility: Supports both 24 VDC and 120 VAC load switching, accommodating diverse auxiliary equipment and building system requirements
• Module Mounting: Compact DIN-rail or panel-mount form factor designed for installation in equipment cabinets and control enclosures
• Fire Alarm Rated: Listed and certified for fire alarm system applications under applicable NFPA 72 and UL standards

Integration and Compatibility

The R-24T relay module is designed for use with System Sensor fire alarm control panels, including the MPS-24 and other compatible platforms. The module expands the relay output capacity of the main control panel without requiring additional panel-mounted relays. Installation requires integration into the panel's auxiliary relay circuit and connection to the control panel's 24 VDC power supply and relay trigger outputs. The tamper circuit must be connected to a supervised zone on the main control panel to ensure continuous monitoring and alert capability.

Typical applications include activation of strobes and horns on secondary circuits, control of door unlock relays, integration with voice evac systems, building automation interface, and sequential activation of suppression system interfaces. The DPDT configuration allows for changeover logic, enabling the same trigger signal to control multiple load states simultaneously—such as opening one circuit while closing another.

Electrical Specifications

Each relay bank is rated for 2 amperes at 24 VDC or 120 VAC, providing sufficient capacity for control-level loads including relay coils, solenoid pilot circuits, and low-current notification devices. The module derives its operational power from the main control panel's 24 VDC supply; no external power supply is required. All field connections use 18–14 AWG screw terminals for secure, code-compliant wiring.

Jerry Tildsen

I've specified the System Sensor R-24T on multiple integration projects where panel relay capacity needed expansion without upgrading the main control unit. The 4-gang DPDT design is straightforward to wire and the tamper protection adds a compliance layer that auditors and AHJs expect in modern fire alarm architectures. The dual-voltage switching is a practical feature—you're not limited to 24 VDC loads, which matters when coordinating with legacy building automation or older horn/strobe circuits still running on 120 VAC.

Technical Highlights:

• Relay Capacity: 4 independent DPDT banks rated 2A @ 24 VDC or 120 VAC per pole, enabling parallel load switching and changeover logic in a single module
• Tamper Supervision: Integrated tamper circuit provides tamper-open alerting to main panel, detecting removal, bypass, or terminal tampering
• Power Integration: Operates directly from main panel 24 VDC supply; no auxiliary power supply required, reducing cabinet clutter and failure points

Deployment Considerations:

• Plan your relay assignment during system design—each bank is independent, so load grouping by floor or functional zone simplifies future modifications
• Verify that your control panel model supports auxiliary relay modules; check compatibility matrix in the panel's engineering manual before ordering
• Connect the tamper circuit to a supervised zone with instant response configured; do not leave it unsupervised or set to delayed response
• Use appropriately rated wire for your load voltage and current—18 AWG is acceptable for most loads under 1A, but 16 AWG is preferred for 2A applications

The R-24T is a reliable expansion option if your main panel relay outputs are fully allocated. It's a straightforward install if your cabinet layout accommodates DIN-rail mounting, and the tamper feature means you're audit-ready from day one. Recommended for integrators working with System Sensor platforms in mid-sized facilities where relay expansion is predictable.