Hochiki Conventional Detector Base, Black, Electronics Free YBN-R/6(BLK)

Overview

A detector base is the part that stays on the ceiling. The wiring lands on the base, and the detector head twists on and off it, so heads can be swapped or serviced without disturbing the cables.

This base belongs to the wider range of fire detector bases and is made for Hochiki's CDX range of conventional detectors. Conventional means devices are wired in zones, and the guide to commercial fire alarm systems explains how that differs from addressable.

How it works

• Electronics free: the base is a set of terminals and contacts with no circuitry of its own, so the detector head does all the detecting.
• Bayonet fixing: the head locates in a bayonet slot and turns to lock, with low insertion force so it goes on easily at height.
• Third terminal: a remote indicator is a separate LED, often outside a locked room, that lights when the detector in that room goes into alarm. That LED is wired back to this base.

Where to use it

The base works from -10 °C to + 50 °C and up to 95%RH, non condensing. Choose black where a white base would stand out, such as a dark ceiling or a black fitting.

What the figures mean in practice

• 8 mm: the base adds very little depth, so the detector sits close to the ceiling.
• 48 ~ 74 mm fixing centres: the spread of screw positions it can take, which gives some freedom when fixing to an existing box.
• 9.5 – 30 V dc: the zone voltage it works within. Allow for voltage drop along the cable on long zones.

Installing it

This is the point installers most often miss. Removing a detector breaks the circuit at that base, so devices further along the zone stop being monitored.

Wire any call points onto the zone first, so they stay connected when a head is off. Square cable clamps take 2.5 mm² cables and hold them firmly.

Planning your system

• Detector heads: pick a CDX detector to suit the room, from the range of fire detectors, smoke or heat as the risk demands.
• Call points: manual call points belong at the start of the zone wiring, ahead of any detector bases.
• Panel: confirm the panel runs conventional zones before choosing parts, and check its zone voltage on long cable runs.
• Other Hochiki parts: browse Hochiki fire equipment for heads, sounders and accessories from the same maker.
• Extras: remote indicators, covers and similar parts are in the fire alarm accessories and components range.