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Collaboration, Voice & AV · Foundational

Contact Closure

A simple control method that opens or closes a dry electrical contact, used for screens, lifts, shades and sensors.

Definition

Relays on a control processor close a circuit to trigger devices such as projection screens or lifts, while digital inputs sense contact closures from occupancy sensors, partition switches or buttons. Contacts are normally open or normally closed. Relays should not switch loads beyond their voltage and current ratings.

Example

A partition sensor closes a contact when the air wall opens, telling the control system to combine two rooms.

Exam tip

Dry contacts carry no voltage of their own; check relay ratings before switching motors directly.

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