Discontinued — No Longer Available New
This model has been discontinued by Aiphone. Shop current Aiphone products → or see the recommended alternatives below.
Aiphone KB-3MRD Master Monitor with Handset
Overview
The Aiphone KB-3MRD is a wall-mounted color video entry intercom master station designed for multi-unit residential, commercial, and institutional installations. As the primary control point in an Aiphone KB-3 system, this unit provides real-time video identification, selective call routing, and two-way voice communication through a dedicated handset. The KB-3MRD features a 4" LCD screen that delivers clear video monitoring of connected door and sub-stations, making it an essential component for buildings requiring secure access verification and tenant communication.
Key Features
- 4" Color LCD Display: Provides clear video identification and real-time monitoring of entry points and sub-station activity
- Full-Duplex Handset Communication: Dedicated handset enables simultaneous two-way voice communication without audio delays or transmission conflicts
- Internal All-Call Chime: Audible notification system alerts occupants to incoming calls from door stations
- Receiver Volume Control: Adjustable audio levels accommodate varying ambient noise conditions and user preferences
- Built-In Low-Light Illumination: Internal lighting enhances display visibility in dimly lit installation environments
- Selective Call Routing: Directs incoming calls to specific stations rather than broadcasting to all units, reducing unnecessary interruptions
- Video Output to DVR: Supplied connector enables video recording integration for security documentation and incident review
- Optional Door Release Control: Compatible with RY-3DL relay for selective activation of electronic door locks (RY-24L available for higher contact ratings)
- Surface or Desk Mounting: Supports direct wall mounting or optional MCW-S/B desk mount for flexible installation configurations
Wiring and Distance Specifications
The KB-3MRD requires 2-conductor, mid-capacity, solid, non-shielded wire (Aiphone #871802). Maximum operating distances vary based on wire gauge: Master station to door station extends 330 feet with 22 AWG wire or 650 feet with 18 AWG wire. From master station to the farthest sub-master station, reach is 165 feet (22 AWG) or 330 feet (18 AWG). Power supply to master station operates at 16 feet (22 AWG) or 33 feet (18 AWG). Power supply to sub-master stations extends 16 feet (22 AWG) or 33 feet (18 AWG).
Door Release Control
The KB-3MRD output supports N/O (normally open) dry contact relay operation rated at 12V AC, 400mA. For applications requiring control of two or three doors, the RY-3DL relay provides appropriate contact ratings. The RY-24L relay accommodates larger contact ratings for high-current lock mechanisms.
System Integration and Compatible Components
The KB-3MRD functions as the master control unit within Aiphone's KB-3 system architecture and operates alongside compatible sub-stations and door modules including the KB-3HRD sub-monitor with handset, KB-3SD audio-only sub-handset, KB-DAR tilt video door station, and audio-only door stations. Video output connectivity enables integration with DVR systems for continuous monitoring and archival recording capabilities.
During system design and deployment planning for multi-unit properties, the Aiphone KB-3MRD serves as the operational hub for entry verification and tenant communication. I've evaluated this master station across residential and light commercial applications where selective call routing and video identification are mandatory for security protocols. The KB-3MRD delivers straightforward functionality without unnecessary complexity, which translates to faster installation and lower training requirements for end users.
Technical Highlights:
- Display and Communication: The 4" LCD display coupled with full-duplex handset communication eliminates the need for supplemental audio equipment; voice and video coexist without interference
- Distance Capability: With appropriate gauge wire, the master station reliably communicates across 650 feet to door stations, supporting larger building footprints without repeaters or signal boosters
- Modular Architecture: The KB-3MRD integrates with both sub-stations and video door modules, permitting incremental system expansion as occupancy or security needs evolve
- DVR Integration: Direct video output connectivity enables third-party recording without additional interface hardware
Deployment Considerations:
- Verify wire gauge and total circuit distance before installation to ensure compliance with Aiphone specifications; undersized wire introduces voltage drop and unreliable operation
- Position the master station in a central, high-traffic area where staff or management can monitor incoming calls consistently; the handset design supports continuous availability during business hours
- If door release integration is required, confirm door lock current requirements against relay ratings (standard 400mA vs. RY-24L for higher draw); undersized relays fail prematurely
- Allocate adequate space for cable routing during retrofit installations; solid, non-shielded wire requires mechanical protection in areas subject to foot traffic or equipment movement
The Aiphone KB-3MRD remains a reliable foundation for access verification systems in environments where straightforward, dependable operation outweighs feature complexity. For integrators standardizing on Aiphone platforms, this master station pairs efficiently with existing KB-3 infrastructure and supports both retrofit and greenfield installations without proprietary configuration tools.
