Relay contact configurations determine how many circuits a 12 V DC switch can control and whether it provides single-pole, double-throw (SPDT) or double-pole, double-throw (DPDT) switching. Choose an SPDT configuration for one changeover circuit, or a DPDT configuration when you need to switch two circuits together, and confirm that the contact voltage and current ratings match the connected load.

Installers should verify that the switch or relay supports the system’s supply voltage, required current draw, trigger voltage, and trigger polarity, such as positive or negative activation. They should also confirm the contact configuration, such as SPDT or DPDT, and the contact rating for the connected load, including its voltage and current.

Use a relay-based 12 V DC switch when a control signal needs to switch another device or higher-current load through SPDT or DPDT dry contacts. Choose a master power switch when the goal is to manually disconnect a control panel or power supply from its battery and AC power, with some modules also providing low-battery cutoff.

12 V DC switches, including relay and master power modules, help control panels and power supplies by switching connected loads through SPDT or DPDT dry contacts, with some modules accepting positive or negative trigger inputs. A master power switch can disconnect battery and AC power, while a low-battery cutoff module can disconnect the battery when its voltage falls below 10 V DC to help protect connected equipment from deep discharge.