NCJ Number
13325
Journal
Security World Volume: 11 Issue: 3 Dated: (MARCH 1974) Pages: 24,46-50
Date Published
1974
Length
6 pages
Annotation
DISCUSSION OF DIFFERENT TYPES OF FIRE ALARM SYSTEMS AND THE MAINTENANCE OF A SECURE BACK-UP IN CASES OF ENERGY CUT-BACKS.
Abstract
THE AUTHOR IDENTIFIES TWO CLASSES OF FIRE ALARM SYSTEMS, AC-OPERATED AND DC-OPERATED. HE THEN COMMENTS ON PROPRIETARY SYSTEMS (THOSE SYSTEMS WHICH EXIST ENTIRELY WITHIN AN ENCLOSED LOCATION OF PERIMETER, SUCH AS A REST HOME OR HOSPITAL). IT IS STATED THAT IN THIS TYPE OF SYSTEM, THERE IS USUALLY A BACK-UP BATTERY SUPPLY TO SEND A MESSAGE THAT THERE IS TROUBLE IN THE SYSTEM. HOWEVER, THE TROUBLE SIGNAL INDICATES AN ABSENCE OF THE SYSTEM'S ALARM CAPABILITY RATHER THAN SIGNALING AN ALARM. STEPS FOR CHECKING OUT SUCH A SYSTEM ARE POINTED OUT, ALONG WITH A DISCUSSION OF THE EFFECTS OF A BROWNOUT (LINE VOLTAGE DROP) ON THE SYSTEM. AN ALARM SYSTEM USING A DC CURRENT IS RECOMMENDED AS A BACK-UP IN CASE OF A BROWNOUT. COMMENTS ARE MADE ON REMOTE AND AUXILIARY ALARM SYSTEMS WHICH CONSIST OF OUTSIDE POINTS, SUCH AS A MANUAL FIRE BOX OR A CENTRAL STATION. THE AUTHOR DISCUSSES THE COMBINATIONS OF AC AND DC OPERATED SYSTEMS USED FOR THESE ALARMS AND THE EFFECTS OF A BROWNOUT ON THIS TYPE OF SYSTEM.