Wierd: open Trouble on module NFS 320

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Thu Feb 25, 2016 6:48 am

Hi guys!

first of all, i am new here, I need help on the nfs 320, i'm not quite expert on this matter especially in installation, but i can do programming in basic way.

I have install 2 modules fcm-1 which carries 34 smoke detectors conventional, the programming was fine and the smoke testing works perfectly. my problem is, there are trouble in both modules it is said "OPEN" on the screen. i am run out of ideas .. i checked the modules it was connected tightly in correct module numbers. i want to make it "system is normal" ..... is there chance that the problem is on wiring? where? and what do i need to do

is there a trick that we can bypass the reminder and make it system is normal? we disconnect the nac for awhile because it will alarm every 15-30secs.

thanks all your advice will be appreciated. please don't get harsh on me. i want to learn about this job. :)
Fire Alarm Technician
Fire Alarm Technician
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Thu Feb 25, 2016 1:37 pm

Do you have the end of line resistors on?
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Fri Feb 26, 2016 9:58 am

I am in no way an expert on these systems. Never worked on one. However, I am fairly good at searching for information.

Are you sure you are connecting smoke detectors to an FCM-1? I ask this because according to the datasheet a FCM-1 is a supervised control relay module for notification appliances - not smoke detectors.
Quote from datasheet DN-6724:B3.
fcm-1.png (10.11 KiB) Viewed 2047 times
If these are 2-wire smoke detectors they should be connected to a FZM-1.
Quote from datasheet DN-6720:C.
fzm-1.png (5.4 KiB) Viewed 2047 times
If you are using the correct module and made a typing mistake, I will expand on chris+s' question. Most of the modules use a 47K ohm EOLR. The FZM-1 uses a 3.9K ohm resistor. Are you using the correct resistor value?
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