Overview
The Apollo 45681-277APO is an XP95/Discovery-compatible addressable sounder base with an integral short-circuit isolator and loop-powered sounder. It accepts an Apollo detector or beacon, or may be used standalone with a blanking cap. Intended for indoor use on intelligent addressable fire alarm loops.

• Built-in short-circuit isolator for loop fault tolerance.
• Two selectable tones; two selectable volume ranges (55–75 dB(A) and 75–91 dB(A) at 1 m).
• Loop-powered — no external supply required.
• XP95 protocol compatible (also supports Discovery & CoreProtocol) with XPert7 addressing.
• Unique acoustic self-test function to verify sounder operation.
• Fits a 4" isolated mounting base; polycarbonate white housing.

Use cases

• Commercial and domestic fire alarm systems using Apollo XP95/Discovery detectors.
• Replacement or upgrade where loop isolation and addressable sounder functionality is required.
• Installers: suitable where a combined detector/sounder base or a standalone sounder base is required.

Compliance & installation

• Designed to meet EN54-3 requirements for fire alarm sounders; consult the Apollo datasheet for full approvals and the latest CE/UKCA marking details.
• Installation and commissioning should be carried out by a competent person in accordance with local regulations and standards (eg BS 5839 series where applicable).
• Refer to the official installation manual/datasheet for full electrical figures, wiring diagrams and siting guidance.