Adding a Fire sounder

[dalewolf]

At college, I've been set a few different questions, which i need to explain how I would install different things. One question I'm unsure of:

Add a sounder to an existing system


can you simply extend the existing system by going into a sounder and spuring off the sounder.

Or do you go into an existing sounder when theres two wires going in, take one pos/neutral out and extend to the new sounder, with cable coming back into original siren.

(if either of these solutions are wrong, how would they affect the system)

would the end of line resistor in the last sounder become affected in any way, if i did either of these???

Any help would be appreciated

 

[Spark123]

You should not branch on a monitored system, all the cables and bells should be wired in sequence. A branch will not be monitored.
I have drawn a quick sketch, in reality fire alarms should have more than one sounder circuit;

http://i215.photobucket.com/albums/cc91/Spark-123/firealarm.jpg

 

[richard271]

In your first option the spur will not be monitored, but the eol will not be affected.
In the second option you are continuing the circuit to include the new sounder and if done correctly it will all be monitored, the new wiring can be 4 core cable with extra connections made in the original sounder casing.

 

[dalewolf]

thanks for the help

 

[rssteve]

i see this topic is a few days old. The fire address could be an addressable loop system where you are allowed spurs normally up to 100m as it is all monitored.

 

[richard271]

In the original post it referred to eol which can only be a conventional system, or an addressable system with conventional sounders.
Never heard that one before as on an addressible system all the devices should be on the loop so that if the circuit is broken they will be fed from either direction, it's not good practice to spur off the loop.