loss of clock and keybus fault

Reply

  #1  
Old 08-14-18, 07:07 AM
Member
Thread Starter
Join Date: Aug 2018
Location: NZ
Posts: 4
Received 0 Votes on 0 Posts
Question loss of clock and keybus fault

Does anyone know about "loss of clock" and "keybus fault" on home alarm systems? I have a DSC PC1864 house alarm that's 5 yrs old and for the past 3 yrs the alarm has had a random intermittent problem that occurs anywhere from once a week to once every few months, both when the alarm is armed and unarmed. First there is a "loss of clock" where the system re-sets the time to 12:00 am. Then within a few minutes the system goes into "keybus fault - call for service" and the entire alarm does not work and emits long beeps. Then after a minute or so the alarm corrects itself and the normal home screen returns with the trouble light on that indicates the loss of clock. The installer removed one-by-one the LCD panels/keypads and left each one removed from the system for weeks. The problem still occurred with each panel removed from the system. He also connected each panel directly to the motherboard and the panels worked fine. Any ideas would be greatly appreciated!
 
Sponsored Links
  #2  
Old 08-14-18, 10:15 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 53,654
Received 421 Votes on 394 Posts
Welcome to the forums.

Make a list of the items you have using AUX power from the panel. That includes glass breaks, motion detectors and items on the data bus... like expansion modules and keypads. You need to add up the current required for these items. You may have to much load on the panel aux power causing the protection circuit to trip and reset.
 
  #3  
Old 08-14-18, 09:11 PM
Member
Thread Starter
Join Date: Aug 2018
Location: NZ
Posts: 4
Received 0 Votes on 0 Posts
Hi Pete. Thank you! Too much load makes sense. There are a lot of sensors, PIRs, keypads, etc connected. I will check this.
 
  #4  
Old 08-14-18, 09:25 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 53,654
Received 421 Votes on 394 Posts
Not sensors..... only things that derive their 12v power off the panel.
 
  #5  
Old 08-14-18, 09:30 PM
Member
Thread Starter
Join Date: Aug 2018
Location: NZ
Posts: 4
Received 0 Votes on 0 Posts
OK I understand now. Thank you.
 
  #6  
Old 08-15-18, 05:33 PM
Forum Topic Moderator
Join Date: Jun 2000
Location: Gainesville, FL, USA
Posts: 16,239
Received 32 Votes on 31 Posts
If your system is 5 years old, and still on the original battery, then you are overdue for a replacement. The battery does more than carry the system on power loss; it also smooths out the demand on the system power supply.
 
  #7  
Old 08-21-18, 06:37 PM
Member
Thread Starter
Join Date: Aug 2018
Location: NZ
Posts: 4
Received 0 Votes on 0 Posts
MrRonFL - Thank you for the added info about the batteries, that is 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
 
Ask a Question
Question Title:
Description:
Your question will be posted in: