Notifier B501BI Addressable Isolator Detector Base – Intelligent Plug-in Base for SLC Loop Protection

The Notifier B501BI Addressable Isolator Detector Base is an intelligent plug-in mounting base designed to improve the reliability of addressable fire alarm systems by providing automatic short-circuit isolation on the signalling line circuit (SLC). When a wiring fault occurs, the integrated isolator disconnects the affected section of the loop while allowing the remainder of the system to continue operating, helping to maintain fire protection and reduce system downtime.

Designed for use with compatible Notifier 851 and 951 Series addressable detectors, the B501BI provides secure detector mounting while enhancing loop integrity. The isolator automatically restores communication once the short circuit has been cleared, simplifying maintenance and minimising disruption to the fire alarm system.

With a compact, low-profile design measuring just 102 mm in diameter and 20.3 mm high, the B501BI is suitable for new installations and system upgrades. Available in white, ivory, and black, it integrates neatly into a wide range of commercial, industrial, healthcare, education, and public building environments.

Key Features:

• Intelligent addressable isolator detector base
• Automatic short-circuit isolation for SLC loop protection
• Compatible with Notifier 851 and 951 Series addressable detectors
• Plug-in design for quick installation and detector replacement
• Operating voltage: 15–28.5 VDC
• Low standby current of less than 150 µA
• Maximum current draw of 17 mA
• Operating temperature: -10°C to +55°C
• Compact low-profile design (Ø102 mm × 20.3 mm)
• Available in white, ivory, and black finishes

Typical Applications:

• Commercial office buildings
• Hospitals and healthcare facilities
• Schools and universities
• Hotels and accommodation
• Shopping centres
• Industrial facilities
• Government buildings
• Addressable fire alarm systems requiring SLC loop isolation