Joining the Firepoint 2 fire alarm control panels to other alarm systems.

Preamble

This document explains the various methods available for joining a Firepoint 2 fire alarm to another alarm system, perhaps in an adjoining building, or to central control room.  The other alarm system does not have to be a Firepoint-2 — it can be any equipment from any manufacturer so long as it has the necessary terminals.  Connecting the Firepoint 2 fire alarm to other fire alarm equipment is not particularly complicated once you know how.

This document does not tell you how to join several Firepoint 2 control panels together in order to create a single, very large installation.  If that is what you need to do then please click here

Background information

Sometimes it is necessary to connect a fire alarm in one premise to the fire alarm in a neighbouring building.  Common situations where this might be necessary include shopping centres and industrial / office units.  A common requirement is that a fire in one unit or one portion of the building should cause an evacuation signal (continuous ringing) to be sounded in that unit and a warning signal (usually intermittent ringing) to be sounded in all the adjacent units.  The system must work in both directions so that a fire in unit A causes a warning signal to be given in unit B and vice-versa.

One complication that can arise with these linked systems, if they are not joined carefully, is that when an alarm occurs, the first fire alarm sends a warning signal to the second fire alarm which then sends another warning signal back to the first panel.  Now panel A is warning panel B which is warning panel A which is warning panel B .....  This very irksome situation is known as "nesting" or "locking in a loop" and if it happens then the only way to get the alarms to silence is to physically disconnect the connecting cables or to power-down one of the alarms.

Nesting two alarms in this way is a sure way of generating customer complaints!

Another problem that can occur when one of the alarms is serviced and the service engineer performs a walk-test.  If the installer has been careless about the method of joining the fire alarm panels then the test alarm on one panel will cause a warning alarm to be issued on the other connected panels.  Once again this is very undesirable and will almost certainly bring complaints from the building occupiers.

With the Firepoint 2 the problems described above do not occur!

The Firepoint 2 fire alarm control panel is designed to be easily connected to other alarm systems without encountering either of the problems outlined above.  Additionally, there are several methods of joining the Firepoint 2 to other fire alarms and so if one method should be unsuitable for some reason one of the other methods can be used instead.

Possible methods of joining a Firepoint 2 to another fire alarm panel

Method name	Advantages	Possible problems
Non-latching alarms using an input unit attached to the loops.	Total electrical isolation between the two systems is possible. The source of the warning can be shown on the display because the input unit can be allocated a descriptive text just like any other detetor.	A Firepoint 2 panel can only connect to two other panels in this way. If it is necessary to connect to more than two other panels then a different method is needed.
Remote evacuate input terminals	Many control panels can be connected together in this way.	Will sometimes require an extra relay to be fitted in order to get proper electrical isolation. If the Firepoint 2 is connected to more than one panel with this method then the source of the warning signal cannot be identified.
Manual ring input terminals	Discussed elsewhere because it does not really apply to the situations considered in this technical note.  Click here to see when it is useful.

Links

The Firepoint 2 fire alarm panel.