Connect two fire alarm panels together

Connect two fire alarm panels together

LARGE NETWORK SYSTEMS will usually require two conductor twisted shielded cable in a Class "A" configuration.

OPTION: 1

We would suggest that hooking TWO CONVENTIONAL PANELS together so that they monitor each other for "trouble", "supervisory" and "alarm" conditions (all of which are required under the present Building Code) requires two separate runs of five conductor cables.  You'll also require two spare initiating zones and unused alarm/trouble relay contacts in each common control.  Mark each five conductor cable end with "FA Interconnect-A" and "FA Interconnect-B" respectively.

At the designated "B" panel, remove the end of line resistors from the two spare zones.  The fire alarm should indicate a "trouble" condition on both zones.  Take the "A" cable and connect the red and black wires to the first spare zone (this will become "A Panel Alarm").  Connect the blue and brown wires (of the same cable "A") to the second spare zone (this will become "A Panel Supervisory").  Reserve the green. Now connect the "B" cable red and black wires to the "common" and "normally open" terminals of the free "alarm" relay.  Take one of the end-of-line resistors you removed from the "A" panel spare initiating zone and connect one end to the "common" terminal of the free "trouble" relay.  Connect the other end of the resistor to the "normally closed" terminal of the "alarm" relay.  Connect the "normally open" terminal of the alarm relay to the "normally closed" terminal of the "trouble" relay with a short piece of wire.  Take the blue and brown wires from "B" cable and connect them to the "common" and "normally open" terminals of the "supervisory relay".  Connect the second "A" panel end of line resistor between the "normally open" and "normally closed" terminals of the same "supervisory relay".

At the designated "A" panel, the fire alarm should indicate a "trouble" condition on both "spare" zones (you have relocated the end-of-line resistors to the "B" panel).  Take the "B" cable and connect the red and black wires to the first spare zone (this will be designated "B Panel Alarm").  The zone trouble will clear when "B" panel is restored to normal "trouble free" condition.  Take the brown and blue "B" wires and connect them to the second spare zone ("B Panel Supervisory").  This zone trouble should clear.  Now take the red and black wires from designated "A" cable and connect them to the "common" and "normally open" terminals of the free "alarm" relay.  Connect one of the "B" panel end-of-line resistors to the "common" terminal of the the "trouble" relay.  Connect the other end of the end-of-line resistor to the "normally closed" terminal of the "alarm" relay.  Connect a short piece of wire between the "alarm" "normally open" and "trouble" "normally closed" terminals.  Connect the remaining "A" cable blue and brown wires to the "common" and "normally open" terminals of the "supervisory" relay.  Connect the last "B" panel end-of-line resistor between the "normally open" and "normally closed" terminals of the same relay.

See diagram (they say a picture's worth a thousand words, after all):

NOTE: This is a suggested method that ensures both fire alarm systems monitor each other for "trouble", "supervisory" and "alarm" events.  In this example, a common "trouble" (i.e. zone fault) on one panel will result in a zone fault on both.  The "originating" panel will have two zone faults in this instance.  As long as the wiring between the two panels remains intact an "alarm" condition will always over-ride a "trouble" (Additional zone programming may be required).  Older panels may not be capable of providing a separate "supervisory" output but it's important that both common "trouble" and "alarm" conditions are shared between them.

Both panels should now be trouble free.  If they're not, check that you've connected everything as noted above.  If the terminal blocks on either panel's "alarm", trouble" or "supervisory" relays are of the "unpluggable" variety, removing any one block will cause a "trouble" condition to appear on both panels.  What do you do with the two pairs of "green" wires left?  Terminate them to the respective panel ground, of course.

Resetting after an alarm event is fairly simple.  Most modern panels allow you to "bypass" or "disable" the alarm relays.  You'll have to do this on only one of the panels (the one that initiated the alarm).  Reset the "follower" first, then come back to reset and re-enable the alarm relay on the initiating panel.

OPTION: 2

When two conventional fire panels have to be interlinked so that when the first fire system activates the second system will also activates, the on board relay contacts can be used in conjunction with an additional external relay.  It is extremely important to prevent ring around, this is where the first system signals the second and then the second signals the first, and can only be reset by resetting both panels at the same time, which is both inconvenient and impractical for the user.

How does it work?

I will base the explanation on the assumption that FAP 1 is the first to activate.

The drawing only shows zone one, therefore assuming zone two or above activates, the sounder circuit on FAP 1 operates, which drives the external relay 1.  The normally open contacts on external relay 1 changes state to the closed position which via the fire resistor (normally 470 ohm) triggers zone one on FAP 2.  When the sounders operate on FAP 2, external relay 2 will be operated.  However, although the relay 2 contacts will change state, the firing resistor will not be seen by zone one on FAP 1 as the connection wiring goes through the normally closed of FAP 1 aux relay which because FAP 1 was the first to activate are now open and hence the circuit is broken.

If possible, make zone one on both panels none latching.  By setting this configuration, when FAP 1 is silenced FAP 2 will automatically reset and then when FAP is reset both panels will return to their quiescent state. However great care has to be given to making the zones none latching.  For example, if the systems are within the same building and either panels are controlling auxiliary equipment such as door release, you must ensure that the doors only lock again on reset and not silence alarms, therefore in our set up if both panels were controlling access doors, the zones would have to remain as latching and then the panels would have to be reset with the following process:-

FAP 1 silence
FAP 2 silence
FAP 2 reset
FAP 1 reset