C-TEC CAST 4-Way Conventional Zone Converter CA740

Overview

Many older buildings have a working conventional fire alarm with sound zone cabling but devices that are due for replacement. This unit lets that cabling carry CAST addressable devices instead.

It sits on the loop of a CAST panel and feeds the old zone circuits as separate isolated circuits. The wider C-TEC fire alarm range covers the panels and devices around it.

How it works

A conventional system reports by zone, while an addressable system reports each device. The fire alarm system guide explains the difference between conventional and addressable systems in plain terms.

The converter takes one loop address and is set up as a CAST I/O when the panel is programmed. Each of its zone circuits then carries CAST addressable devices.

On the front, each group of four zones has its own polling and isolator lights, so an engineer can see at a glance which side of the unit needs attention.

Where to use it

Retrofit sites are the natural home, for example a nursing home where conventional devices are swapped in situ for addressable ones. As a rule, keeping the wiring avoids lifting floors and chasing walls in occupied rooms.

It is rated IP30 and works from -10ºC to +55ºC, so it belongs indoors in a dry space.

What the figures mean in practice

• Under 500 m per zone: a long existing zone run may need checking before it is reused.
• 20 devices per zone: count the devices on each old zone before you swap them over.
• 8 zones maximum: a building with more than four zones needs the extender PCB, which takes its own loop address.

Installing it

The plastic enclosure can be surface or flush mounted and leaves ample space for loop and zone cabling. It measures 380 W x 235 H x 96 D mm and weighs about 1.5 kg.

As a rule, test each old zone cable for insulation and continuity before new devices go on it. This work is for a competent fire alarm engineer.

Planning your system

The converter needs a C-TEC XFP/ZFP CAST addressable panel. For more than four zones, add the CA740PCB extender PCB.

One such CAST panel is the C-TEC XFP502/CA addressable fire panel.

On each zone, fit CAST or CAST-PRO devices, for example detectors, sounders and manual call points from the CAST range. Other loop add-ons sit with the fire panel modules and interfaces.

Standards and ratings explained

BS 5839-1 is the UK code of practice for fire detection and alarm systems in non-domestic buildings. The converter fully complies with its requirements while keeping loop and individual zone circuit integrity.

IP30 means protection against solid objects of 2.5 mm and larger, with no protection against water.