Back to Basics: Fire Alarm Systems

For many fire departments false fire alarms have become a nuisance and have lead to changes in response policies due to the number of alarms. The response may limit the number of units on the initial alarm, only the first due engine responds with lights and sirens, or none of the units respond with lights and sirens. Once the crews arrive on the scene of the alarm, there is typically an investigation on the cause of the alarm and if necessary the fire is extinguished. Many times, the cause is undetermined or unfounded and the system is reset and the companies return back to quarters. With false alarms, many communities begin to penalize building owners when the department has responded to a predetermined amount of false alarms. Many times the owner will have the alarm system serviced or may elect to change the procedures for the alarm company in a non approved fashion.

A fire alarm system that has been designed, installed, and maintained will provide a system that is not prone to false alarms. Properly designed fire alarm systems begin with the building owner or architect soliciting for an alarm company to design and install a fire alarm system. The designer should be show competencies in design of fire alarm systems and have credentials for the design. Credentials may come in the form of National Institute for Certification in Engineering Technologies (NICET), Professional Engineer, local or state certification as an alarm company. Proper credentials ensure that the designer has a background in commercial fire alarm applications. The fire prevention bureau has more control of fire alarms that are installed in the commercial setting over residential systems. The influence on fire alarms in the residential setting are typically through education of home owners as compared to enforcement powers in commercial buildings.

Because there are differences in the requirements found in model building and life safety codes, the designer must be capable in understanding code requirements and equipment specifications. The first exposure a municipality has to a fire alarm system is the plan review process. A complete plan review is the foundation for the overall performance in the system. The fire prevention bureau should be trained in fire alarm plan review and the requirements of the system. Basic fire alarm submittals should include:

  • Scope of work including construction type and use group classification
  • Construction drawings commonly referred to as shop drawings which include the use of the room, and location of all alarm devices with wiring locations.
  • Fire alarm control equipment including manufacture information
  • Line or riser diagram which indicates all of the devices on a single sheet of paper
  • Power connections including secondary power
  • Voltage drop calculations including cable (wiring) size based on the shop drawings or riser diagram
  • Battery calculations
  • Annunciation of the alarm system or zone nomenclature
  • Details on the ceiling height and construction
  • Any interface to other fire safety functions
  • Copy of the preliminary record of completion

These items are the foundation for a basic alarm system design. Contractors who struggle to provide this documentation at plan review may provide an inferior system or lack the skills necessary in proper system design. The plan reviewer will look for code compliance on the documents utilizing the adopted fire code which typically references National Fire Protection Association (NFPA) 72, National Fire Alarm Code. This standard is the basis for "application, installation, location, performance, inspection, testing, and maintenance of fire alarm systems, fire warning equipment and emergency warning equipment, and their components" (Scope of NFPA 72). The plan reviewer shall ensure code compliance and if the documents do not meet the requirements of the jurisdiction the plans should be returned to the contractor for corrections.

After the plan review process the contractor will begin work on the fire alarm system. Communities vary on the inspection requirements which may include a rough wiring inspection, device placement, and system operations test. During the wiring inspection the inspector shall ensure the proper size wiring has been installed be the plan review and voltage drop calculations. The wire is located in the proper conduit or wire chase and is properly secured. The manufacture of the wire may have special provisions on the listing of the wire including the wire must not be painted. The inspector can review this information on the catalog cut sheet submitted at the time of the plan review.

Near the end of a project is when a system acceptance test is conducted. It is recommended that the alarm company provide two technicians at time of final testing and fire prevention staff should work closely with other inspectors in the community. This could include electrical, building, or mechanical inspectors. One technician will be located at the fire alarm control panel and the other will activate the devices as necessary in accordance with NFPA 72 which outlines the testing requirements of alarm devices. Manufacture installation instructions can also provide specific details on acceptance testing of devices. The final acceptance should test all devices to ensure the component produces the desired results. This includes proper addressing of the devices on the control panel, proper type of alarm signal (alarm, supervisory, or trouble). The contractor should also provide training to the owner on the alarm system which includes a copy of the construction documents (as-builts or record drawings), complete record of completion, copy of any software for the control system, and maintenance schedule.

Maintenance of an alarm system is critical for the performance of the system. NFPA 72 outlines the minimum requirements of inspection and maintenance of systems and the responsibility typically lies with the building occupant or owner. Inspectors who conduct "annual" fire inspections should ensure the business owner is educated on the importance of proper fire alarm system maintenance and during the course of a year. Fire prevention staff and operations staff should work together when false alarms occur. The company and officer should investigate fire alarms to determine the cause of the alarm. The findings should be reported in the reporting software of system utilized by the department. When multiple responses to an occupancy occur, communication should take place between operational personnel and fire prevention personnel for follow-up.

Fire alarm systems are a great tool for notifying fire department resources about a fire, system activation, or alarm condition. Unfortunately, too many false alarms have allowed fire department staff to lower their guard. By ensuring proper design, installation, and maintenance of a system, fire prevention staff can help reduce the number of false alarms our companies respond to. Companies which respond to fire alarms that are false can assist fire prevention bureau by investigating the alarm and providing follow-up information to fire prevention.

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Michael O'Brian has a varied career in the public and private sectors with an emphasis on code administration and enforcement for the last 10 years. Currently he is working for Farmington Hills, MI, Fire Department as a Staff Lieutenant and is the president of Code Savvy Consultants, a municipal plan review and consulting company.

He is the creator of a dynamic web page called www.inspector911.com which is designed to assist local inspectors by providing resources, information, checklists and up to date news. He has a bachelor of science degree in public safety administration from Eastern Michigan University and can be reached via email at mobrian@inspector911.com

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