BY STANFORD UNIVERSITY

FIRE MARSHAL’S OFFICE AT

ENVIRONMENT HEALTH & SAFETY DEPT.

Fire Alarm System Basics

JOE LEUNG University Fire Marshal

Manager, Fire Safety Program

AARON MCCARTHY Senior Fire

Protection Engineer

ROBERT PORTERFIELD Fire Protection

Engineer

JENNIFER LEE Fire Protection

Engineer

JARNAIL DHALLA Fire

Protection Engineer

Assistant University Fire Marshal

RALPH DURHAM University

Fire Inspector FRANK “MO” MIRANDA Fire

Systems Supervisor

FRANK GARDNER

Fire Systems Lead Technician

RON MORRISON Senior Fire Sprinkler Technician

CHRIS FRAZIER

ARTHUR “RICKEY” JOHNSON

RICH WILKINS

JOE JACKSON

MIKE ARMSTRONG

JAMES BAXLEY

JASON LOPEZ

CARLOS GONZALEZ

ZEEB “DAVID” GUARNEROS

RUDY GARAY

BRANDON MCCLINTOCK

Fire Sprinkler Technicians

Fire Alarm Technicians

Fire Extinguisher Technicians

Building C

JESSE TORRES

Fire Alarm Systems

Several main functions:

Provide a means to identify a developing fire through automatic methods.

They alert building occupants to a fire condition and the need to

evacuate. Another common function is the transmission of an alarm notification

signal to the fire department or other emergency response organization. Fire alarm systems may also shut down electrical, air handling equipment

or special process operations, and they may be used to initiate automatic suppression systems.

Fire Alarm Systems

Requirements California Code of Regulations has 28 sections/titles. Title 24: California Building Standards

Part 2: California Building Code Part 3: California Electric Code Part 9: California Fire Code

• Chapter 9 lists basic requirements based on occupancy type.

Depending on the anticipated fire scenario, building and use type, number and type of occupants and criticality of contents and mission There are 3 common types of systems: Conventional, Addressable, Analog Addressable. Analog addressable type is not commonly used.

Fire Alarm System Types

Conventional Lower initial equipment

costs. Defined location of

fire/alarm not provided at the panel or central station

Can be easier to program. Limited expansion

capability.

Addressable Easier to install. More system status

information at the panel and central station.

Input/Output programming much more flexible.

Usually much more room available to expand.

Conventional Systems

Wiring must be installed in a supervised manner either Class A, or Class B with an EOLR. Alarm/Trouble conditions are annunciated by zone only. Inspection is required to determine the device in alarm/trouble

Zone #1

4.7K EOLR

4.7K EOLR

Zone #2

NAC #1

FACP

Addressable Systems

Each point on the SLC loop is given a unique address when installed. Alarm/Trouble conditions are annunciated by a unique message for each device.

001 002

003

004

005 006

FACP

FIRE FIRE

SILENT KNIGHT

Addressable Pull Station

Addressable Relay Module

(Fan Shutdown)

Addressable Heat Detector

4.7K EOLR

NAC #1

Addressable Smoke Detector

Addressable Input Module (Waterflow)

Addressable Smoke Detector

Fire Alarm System Principles

Manual fire detection is the oldest method of detection. In the simplest form, a person yelling can provide fire warning. In buildings, however, a person's voice may not always transmit throughout the structure. For this reason, manual alarm stations are installed. The general design philosophy is to place stations within reach along paths of escape/egress. It is for this reason that they can usually be found near exit doors. The advantage of manual alarm stations is that, upon discovering the fire, they provide occupants with a readily identifiable means to activate the building fire alarm system. The alarm system can then serve in lieu of the shouting person's voice. They are simple devices, and can be highly reliable.

Fire Detection Principles

Automatic Detectors – Spot type

Fire Detection Principles

Automatic Detectors – Photoelectric

NFPA 72, Light Scattering Smoke Detection. The principle of using a light source and a photosensitive sensor arranged so that the rays from the light source do not normally fall onto the photosensitive sensor. When smoke particles enter the light path, some of the light is scattered by reflection and refraction onto the sensor. The light signal is processed and used to convey an alarm condition when it meets preset criteria.

Fire Detection Principles

Automatic Detectors – Photoelectric

A – Light Source

B – Photo Sensor

In the normal case, the light from the light source on the left shoots straight across and misses the sensor. When smoke enters the chamber, however, the smoke particles scatter the light and some amount of light hits the sensor.

Fire Detection Principles

Automatic Detectors – Ionization This type is better at detecting the smaller amounts of smoke produced by flaming fires. An ionization chamber consists of two plates with a voltage across them, along with a radioactive source of ionizing radiation.Inside the ionization detector is a small amount (about 1/5000th of a gram) of Americium-241. This radioactive element has a half-life of 432 years, and is a good source of alpha particles.

NFPA 72, Ionization Smoke Detection. The principle of using a small amount of radioactive material to ionize the air between two differentially charged electrodes to sense the presence of smoke particles. Smoke Particles entering the ionization volume decrease the conductance of the air by reducing ion mobility. The reduced conductance signal is processed and used to convey an alarm condition when it meets preset criteria.

Fire Detection Principles

Automatic Detectors – Ionization

The alpha particles generated by the americium ionize the oxygen and nitrogen atoms of the air in the chamber. To "ionize" means to "knock an electron off“ an atom ending with a free electron (with a negative charge) and an atom missing one electron (with a positive charge). The negative electron is attracted to the plate with a positive voltage, and the positive atom is attracted to the plate with a negative voltage (opposites attract, just like with magnets). The electronics in the smoke detector sense the small amount of electrical current that these electrons and ions moving toward the plates represent.

When smoke enters the ionization chamber, it disrupts this current -- the smoke particles attach to the ions and neutralize them. The smoke detector senses the drop in current between the plates and sets off the horn.

Fire Detection Principles

Automatic Detectors – Combination

NFPA 72, Combination Detector. A device that either responds to more than one of the fire phenomena or employs more than one operating principle to sense one of these phenomena. Typical examples are a combination of a heat detector with a smoke detector or a combination of rate-of-rise and fixed temperature heat detector. This device has listings for each sensing method employed.

Combination detectors contain more than one element which responds to fire. These detectors may be designed to respond from either element, or from the combined partial or complete response of both elements. An example of the former is a heat detector that operates on both the rate-of-raise and fixed-temperature principles. Its advantage is that the rate-of-rise element will respond quickly to rapidly developing fire, while the fixed-temperature element will respond to a slowly developing fire when the detecting element reaches its set point temperature.

Building Notification

Notification Appliances

NFPA 72, Notification Appliance. A fire alarm system component such as a bell, horn, speaker, light or text display that provides audible, tactile, or visible outputs, or any combination thereof.

NFPA 72, Audible Notification Appliance. A notification appliance that alerts by the sense of hearing.

NFPA 72, Visible Notification Appliance. A notification appliance that alerts by the sense of sight.

Fire Alarm Circuit Classes

NFPA 72, Classes. Initiating device circuits, notification appliance circuits, and signaling line circuits shall be permitted to be designated as either Class A or Class B, depending on their performance during non-simultaneous single circuit fault conditions as specified by the following:

(1) Initiating device circuits and signaling line circuits that transmit an alarm or supervisory signal, or notification appliance circuits that allow all connected devices to operate during a single open or a non-simultaneous single ground fault on any circuit conductor, shall be designated as Class A (2) Initiating device circuits and signaling line circuits that do not transmit an alarm or supervisory signal, or notification appliance circuits that do not allow all connected devices to operate beyond the location of a single open on any circuit conductor, shall be designated as Class B

Class B Initiating Device Circuit

4.7K EOLR

4.7K EOLR

Class B Notification Appliance Circuit

Conventional Class B Circuits

FACP

Single open circuit condition causes a trouble on the panel and renders all devices beyond the fault inoperative.

Class B Initiating Device Circuit

4.7K EOLR

4.7K EOLR

Class B Notification Appliance Circuit

Conventional System Class B Circuits

FACP

Class A Initiating Device Circuit

Class A Notification Appliance Circuit

Class A Circuits

End of line supervision resistors are not necessary as the loop returns to the panel and is driven from both ends.

FACP

Class A Initiating Device Circuit

Class A Notification Appliance Circuit

Class A Circuits

Single open circuit condition causes a trouble on the panel. All devices on the loop remain operative.

FACP

Licensing Requirements

Requirements for technicians per NFPA 72

State Certified in Fire/Life Safety or Electrician

NICET Certification

Fire Alarm Manufacturer Certification

• FireFinder XLS (252 devices, expandable to 2500 devices)

• NFS-320 (318 devices) • NFS2-640 (636 devices) • NFS2-3030 (3,180 devices)

Fire Alarm Panel Options

3 Types of Fire Alarm Signals

1. TROUBLE • Local sounding (beeping) on FACP and Annunciators • No horn/strobes sounding or flashing • Low battery, smoke detector removed, ground fault, open horn circuit,

etc. • Alarm Tech responds

2. SUPERVISORY • Local sounding (beeping) on FACP and Annunciators • No horn/strobes sounding or flashing • Sprinkler valve closed, duct detector activated*, low-air on pre-action

system • Fire Department responds

3. ALARM • All horn/strobes sounding and flashing • Building occupants to evacuate • Smoke detector, manual pull, waterflow, duct detector, or heat detector

activated • Fire Department responds

SUFMO Fire Alarm Techs

Preventive Maintenance

Semiannual visual inspections

Annual testing

Annual fire smoke damper testing (with HVAC)

Quarterly student evacuation drills (with Inspectors & FPEs)

Monthly evacuation drills at child day care centers (with Inspectors)

Annual elevator recall testing (with Kone A)

Construction Projects

Initial acceptance testing with FPEs per Stanford FDG and applicable codes

Final acceptance testing with FPEs and the Authority Having Jurisdiction (Santa Clara County or Palo Alto)

Isolating system components for contractors to work (i.e., SESI)

Other Responsibilities

Respond to all fire system troubles 24/7 (On-Call)

Provide fire department assistance with technical issues or nuisance alarms

Program fire alarm systems with laptop and proprietary software

Troubleshoot and repair fire alarm systems

Maintain the Remote Monitoring Station

Providing services to

University Main Campus

Various off campus locations (Hopkins, Boathouse, Porter Drive, and others)

Fire smoke damper

There is a smoke detector up there?

No smoking please

Remote Monitoring Station

Mesh network Licensed FCC Radio Frequency (RF) Antennas and receiving equipment in Building C Dispatcher located at Palo Alto Communications (250 Hamilton) Fire Department contacted by dispatcher directly Over 300 monitored systems

ESF BLDG C

Remote Alarm Transmitter (RAT)

Mesh Network Concept

Antennas on Building C Palo Alto Communications

Benefits of RF Mesh Network

All of these are monitored systems

ESF

• Speed (5-10 seconds) • Monthly expenses • Reliability • Natural disasters

Monitoring equipment in Building C

Key Changes 2010/2013 Edition

Renaming NFPA 72 - Both New Sections on Gas Detection - Both Direction on Intelligibility- Both Low Frequency sounders - 2013 Emergency Communications Systems (ECS) Chapter Circuits and Pathways Chapter Emergency Control Functions and Interfaces Chapter New Annex – System Performance and Design Guide

Key Changes 2013 Edition

14.2.10 Test Plan

• 14.2.10.1 A test plan shall be written to clearly establish the scope of testing14.2.10.2 • The test plan and results shall be documented

with the testing records. • Annex material to explain test plan

Key Changes 2010/2013 Edition

Section 23.8.4.8 was revised to require signals from CO

detectors or CO detection systems to initiate a CO alarm signal (Temporal – 4).

A new exception to 23.8.4.8 permits supervisory signals where permitted by the building response plan.