IL Fire Alarm flashcards

33 cards. Read the term and the definition here. The deck at the top of this page is optional.

IDC

Initiating Device Circuit: the supervised wiring path from the fire alarm control unit to initiating devices such as smoke detectors, heat detectors, and manual pull stations.

NAC

Notification Appliance Circuit: the power and supervision path from the control unit to notification appliances such as horns, strobes, and speakers.

Addressable system

A fire alarm system in which each initiating device and notification appliance has a unique address, allowing the control unit to identify the specific device in alarm or trouble.

Presignal

A feature that routes alarm signals to a designated location for acknowledgment before general occupant notification, delaying the general alarm within NFPA 72 time limits.

Positive alarm sequence

A NFPA 72 feature allowing 15 seconds for acknowledgment and up to 180 seconds total for investigation before automatic general alarm notification, if the sequence is completed.

Conventional zone limits

In a conventional system, a zone must not exceed 22,500 square feet, must not span more than one floor, and must be separately annunciated at the control unit.

Spot smoke detector spacing

On smooth ceilings, spot-type smoke detectors are spaced no more than 30 feet apart, with the first detector within 15 feet of any wall.

Heat detector spacing

Ordinary-rated heat detectors are spaced up to 50 feet apart on smooth ceilings, reduced 4 percent per foot of ceiling height above 10 feet.

Rate-of-rise detector

A heat detector that responds to a rapid temperature increase, typically about 12 to 15 degrees Fahrenheit per minute, rather than a fixed temperature setpoint.

Pull station height

Manual fire alarm pull stations are mounted 42 to 48 inches above the finished floor, within 5 feet of exit doorways, and unobstructed along the egress path.

Audibility requirement

Notification appliances must produce 15 dBA above ambient or 5 dBA above maximum ambient lasting 60 seconds, whichever is greater, measured at 10 feet.

Strobe candela

Visible notification appliance intensity selected from the NFPA 72 room-size table; a 20-by-20-foot room typically requires a 15 candela strobe.

Duct smoke detector

A detector installed in an HVAC duct with sampling tubes spanning the duct width, listed for the air velocity and supervised for airflow and power.

Supervisory signal

A signal indicating an off-normal condition of a system component, such as a closed sprinkler valve or low air pressure, annunciated distinctly from alarm and trouble.

Class A circuit

A supervised circuit that returns to the control unit so a single open conductor does not disable the circuit, also called Style D or Style X.

Class B circuit

A two-wire supervised circuit with an end-of-line resistor; an open conductor disables all devices beyond the break, also called Style B or Style Y.

Voltage drop formula

Vdrop equals two times current times conductor resistance per foot times one-way length, used to verify the last appliance receives its listed minimum voltage.

Battery sizing

Required ampere-hours equal standby current times standby hours plus alarm current times alarm hours, with a 20 percent aging factor applied.

EOL resistor

End-of-line resistor sized to the control unit; a missing or incorrect resistor produces a trouble condition on a supervised circuit.

Power-limited circuit

A circuit whose power output is limited per NFPA 70 Article 725, allowing reduced wiring methods but requiring separation from non-power-limited circuits.

Ground fault detection

A control unit function that annunciates a trouble when conductor-to-ground impedance falls below the listed threshold, commonly around 10 kilohms.

Smoke detector testing

Annual sensitivity testing with a listed method; detectors out of their listed sensitivity range, such as 0.5 to 3.5 percent per foot obscuration, are recalibrated or replaced.

Record of completion

A NFPA 72 document signed by the installing contractor and witness confirming the system was installed and tested per the design and applicable standards.

Battery load test

Applying the calculated alarm load for the listed duration, typically five minutes, and verifying terminal voltage remains above 85 percent of nominal.

Inspection frequency table

NFPA 72 Table 14.4.3.2 lists intervals: monthly for control unit indicators, quarterly for waterflow devices, semiannually for valve tamper switches, annually for detectors.

Detector clearance

Initiating devices require clearance from obstructions, including 18 inches below sprinkler deflectors, to ensure proper smoke or heat entry into the sensing chamber.

NFPA 70 Article 760

The National Electrical Code article governing fire alarm wiring, divided into general, non-power-limited, and power-limited fire alarm circuit parts.

High-rise threshold

NFPA 101 generally requires fire alarm systems in high-rise buildings, commonly defined as 75 feet or more above the lowest level of fire department access.

Raceway fill limit

NFPA 70 Chapter 9 limits raceway fill to 40 percent for three or more conductors, and EMT must be supported within 3 feet of boxes and every 10 feet.

NFPA 1 fire code

The Fire Code adopts NFPA 72 by reference and adds requirements for system maintenance, impairment procedures, and hot work fire watch.

Illinois contractor license

The Illinois Office of the State Fire Marshal requires a state fire alarm contractor license to install, alter, or repair fire alarm systems in Illinois.

Illinois technician CE

Licensed Illinois fire alarm technicians must complete continuing education, commonly eight hours per renewal cycle, to maintain their license with the State Fire Marshal.

Local AHJ permits

Illinois jurisdictions such as Chicago and Cook County may impose additional permitting, plan review, and licensing requirements beyond state law before installation begins.