Fault with caddx nx8e

Reply

  #1  
Old 04-24-19, 01:06 AM
Member
Thread Starter
Join Date: Apr 2019
Location: Greece
Posts: 3
Fault with caddx nx8e

Hello,
I have a Caddx NX8E alarm system installed by the previous house owner in Greece 8 years ago. The system recently has the following problem:When zone 4 closes, zone 12 (which should be closed) appears open for an hour or so and then appears closed. Also, during that hour of the erroneous behaviour, if zone 12 opens, then it appears closed while zone 4 appears open. The behaviour of the system is normal when zone 4 opens, then zone 12 works at id should. When we arm the system to exit (assuming that both zones 4 and 12 are and appear closed), then after some time we get alarm signal from either zone 4 or 12 or both.Zone 4 is made up of 4 door magnetic contacts and zone 12 is made up of 2 motion detectors.I've tried to connect the circuit of zone 4 to a different zone (say zone 6) on the board, but the result is the same, ie zone 6 and 14 have show the above erroneous behaviour.I've also connected a different circuit to zone 12 while keeping the original connection of zone 4, but the problem (between zones 4 and 12) remains.Any idea what's happening and how it can be fixed? (all connections are hard wired)Many thanks
 
Sponsored Links
  #2  
Old 04-24-19, 02:35 AM
Forum Topic Moderator
Join Date: Jun 2000
Location: Gainesville, FL, USA
Posts: 16,018
Likes Received: 10
Are these zones on the base panel and a zone expander board; or are they on a system with zone doubling enabled? I suspect the latter.

Need to know which to advise you, accurately.
 
  #3  
Old 04-24-19, 05:31 AM
Member
Thread Starter
Join Date: Apr 2019
Location: Greece
Posts: 3
Many thanks. We have 16 zones and the board has zone ports 1-8, on each port there are two wires, so I would imagine that there is zone doubling with resistors.
 
  #4  
Old 04-24-19, 03:35 PM
Forum Topic Moderator
Join Date: Jun 2000
Location: Gainesville, FL, USA
Posts: 16,018
Likes Received: 10
Yes, this is a zone doubled system zone 4 should have a resistance of 3.74K ohms, and zone 12 should have a resistance of 6.98K ohms.

Most likely, one, or more, of the contacts or motions on the two loops is either failing, or has developed a high resistance in the micro switch or relay that's inside, thus changing the circuit resistance (which is fairly narrowly set for zone doubling to work).

The best way to pin this down, is to eliminate one contact or motion at a time, jumping the wires at the device together, and see if the behavior stops. When the circuit is stable, then you know which contact or motion to replace.

There is an outside chance that the field wiring is damaged, but that's a long shot.
 
  #5  
Old 04-24-19, 10:47 PM
Member
Thread Starter
Join Date: Apr 2019
Location: Greece
Posts: 3
Many thanks. This is very helpful.
 
Reply

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread
Display Modes