7A relay modules with single-pole, double-throw (SPDT) contacts switch one circuit between two output paths, making them useful for selecting between normally open and normally closed states. Double-pole, double-throw (DPDT) modules switch two circuits together, which can help coordinate separate loads or signal paths from one trigger while keeping the contacts electrically isolated.

Check that the relay module’s operating voltage matches the system, with many options supporting selectable 12 or 24 V DC operation. Confirm the trigger type and level, since modules may accept positive or negative activation, while trigger voltage and current requirements vary by model, such as 4.5 to 24 V DC and approximately 1.2 mA for sensitive relay inputs.

7A relay modules let security, access control, and automation equipment switch connected loads through SPDT or DPDT Form C dry contacts, helping separate control signals from the devices being switched. Many support 12 or 24 V DC operation, positive or negative triggering, and LED status indication, while timer-equipped versions add adjustable delay or one-shot control for applications such as door releases, alarms, and lighting.

When selecting a single-relay module, compare SPDT or DPDT Form C contacts, twelve- or twenty-four-volt DC operation, positive or negative triggering, terminal style, LED status indication, and mounting options such as adhesive tape or snap track. For multi-relay applications, look for grouped breakaway modules, removable terminal blocks, plug-in harnesses, enclosure mounting, or output expanders that combine voltage outputs and relays.