C-TEC ActiV Relay Base with Diode, 1A @ 24 VDC Relay, Fire Detector Base C4408DR

Overview

A detector base is the part fixed to the ceiling, and the detector head twists into it. This C-TEC base adds a relay, so the same point that detects a fire can also switch another system.

It suits installers who want a local action at the detector, such as releasing a held-open door or telling a CCTV system that something is happening.

How it works

• Relay: a relay is an electrically operated switch. Here it changes state when the detector's remote LED output turns on, which happens in alarm.
• Changeover contacts: NO means normally open, C is common and NC is normally closed. Use NO to make a circuit on alarm, or NC to break one.
• Diode: the diode version is for systems that need head out monitoring, so removing a head can be reported. Where that is not required, C-TEC offers the C4408R non-diode relay base.
• Locking: an integrated detector and base locking mechanism, with a head removal tool and an ID tag, helps keep heads in place and identified.

Where to use it

Typical uses are door retaining systems, CCTV and security systems that should respond when a nearby detector operates.

The IP42 rating points to dry indoor ceilings. In most buildings, kitchens, plant rooms and outdoor canopies call for other equipment.

What the figures mean in practice

• 1A @ 24 VDC: the contacts are for low voltage signals and small loads, such as a door holder circuit or an input on another system. They are not for switching mains.
• 2.5mm cable: the terminals take up to 2.5mm fire rated cable, which covers the usual loop cable sizes.
• 102.2mm x 30mm: the base is shallow, and the detector head adds its own depth once fitted.

Installing it

The supply wiring is 2-wire monitored and polarity sensitive, so keep +V and 0V the right way round on every base. The click and twist fitting and the extra working space make terminations easier.

Because the ActiV LED strips give a 360° view, the base can go on the ceiling in any orientation. A BF318 remote indicator can be wired to the remote LED terminals where the detector is out of sight.

Planning your system

Each relay base needs a detector head from C-TEC's ActiV range.

One example is the C4403A1R rate-of-rise heat detector. As a rule, check the head type against the room before ordering, smoke or heat.

For bases without a relay, compare the C4408D diode base. More choices sit in the fire detector bases range and across C-TEC detectors.

The guide to fire alarm systems explains zones and categories when planning a wider system.

Standards and ratings explained

• EN54: the EN standard series for fire detection and alarm parts. This base is certified to the relevant parts of EN54 by Intertek, as part of the ActiV detector certifications.
• UL94 V-2: a flammability rating for plastics. The white polycarbonate housing is rated to it.
• IP42: protection against objects over 1mm and against dripping water when tilted, which suits indoor use.