SMOKE DETECTOR INSTALLATION WIRING GUIDE-NFPA 70 ARTICLE 760
The Guideline for Smoke Detector Installation Wiring as per Manufacturer Instruction and NFPA 70 Article 760
In the Fire Alarm System, smoke Detector installation wiring should as per international standard like NFPA 70 article 760 and NEC- National Electrical Code and of course followed by manufacturer instruction manual wiring diagram.
You must be considering that smoke detector installation wiring for fire alarm system is very different from typical House Wiring or Electrical Wiring system. The main purpose of fire alarm system wiring is to be able each sensing detector like smoke detector to continuous electrically supervision.
To make sure the fire alarm system completely operating without any trouble, the very first and basic rule is to follow the manufacturer’s instruction on smoke detector installation wiring diagram.
Smoke Detector Installation Wiring Techniques
The rules of electrical supervision of smoke detectors are not very complex. However, the technician should be familiar and well experienced in the fire alarm system installation works.
The best and easy technique for smoke detector installation is follow the manufacturer’s wiring installation guide. Manufacturer’s wiring guide shows connections in a certain manner to provide accommodation of supervision requirements.
Over-emphasizing the manufacturer’s wiring guide, portion of the circuit may not work for proper supervision, while a short or open circuit occurs.
Smoke Detector Installation Wiring Guidelines
In the incorrect portion of the above figure wiring diagram are shown a very simple mistake known as T-tapping wiring. In first portion of figure indicated incorrect wiring, smoke detector-1 is wired as T-tapping. This T-tapping is very correct wiring technique in typical electrical wiring system, but not in smoke detector installation wiring. This smoke detector may operate correctly in alarm conditions, but if disconnected from the wiring no trouble would be detect in fire alarm system.
In the correct portion of the above figure shown correct installation wiring method for smoke detector-1 where fire alarm panel will indicate trouble if any loss of supervision occurs in any point of the circuit.
Also some smart fire alarm systems are available in the markets that allow T-tapping smoke detector installation wiring. Finally, before the system put into operation, should check the short circuit, open circuit, grounding and each detector as per manufacturer’s instructions.