Alpha 4851-S Main Control Unit for Up to 8-Master Stations and 512 Remote Stations

For facility managers and security integrators who need a robust, scalable backbone for intercom and entry systems, the Alpha Communications 4851-S main control unit delivers dependable centralized control. This intercom control unit supports up to 8 master stations and 512 remote stations, giving you the capacity to deploy expansive entry and monitoring networks across campuses, multi-tenant buildings, healthcare sites and industrial facilities. Engineered with a built-in battery backup (BBU), PBX input and relay interfaces, the 4851-S maintains communications and access during power events and integrates seamlessly with telephony and access-control hardware. Rated to operate between 105–132V and 32°F–120°F, it provides consistent performance in typical equipment room conditions. The compact 18" x 24" x 4" profile fits standard racks and reduces footprint while centralizing control for security, surveillance and monitoring workflows. Choose the Alpha 4851-S to simplify installation, improve system uptime and scale your intercom/entry deployment with confidence. Contact our sales team to configure the unit for your access control and security monitoring application.

• Scalable control for large deployments: supports up to 8 master stations and 512 remote stations to grow with your site
• Built-in BBU and PBX input with relay support ensure continuous operation and easy telephony integration for reliable access control
• Compact rack-friendly design (18" W x 24" H x 4" D) saves equipment room space while simplifying installation
• Wide operating range (105–132V, 32°F–120°F) for stable performance in commercial security and surveillance environments
• Centralized management for streamlined monitoring, entry control and integration with CCTV, access control and building systems