- Distinguish between alarm, trouble, and supervisory signals
- Explain FACP labeling and annunciator requirements
- Compare conventional zone systems with addressable systems
- Describe panel features including reset power, latching, and pre-signal
Lesson 1
Signal Types - Alarm, Trouble & Supervisory
Three Signal Categories
Fire alarm control panels generate three distinct signal types, each with specific priorities, indicators, and response requirements.
Alarm Signal
Priority: Highest
Indicator: Red LED, continuous audible
Cause: Initiating device activation
Action: Evacuate, notify fire department
Trouble Signal
Priority: Medium
Indicator: Yellow LED, pulsing audible
Cause: System fault (open, ground, power)
Action: Investigate and repair
Supervisory Signal
Priority: Lower
Indicator: Yellow LED, distinct tone
Cause: Abnormal condition (valve closed)
Action: Investigate and restore
Alarm Signals
An alarm signal indicates that an initiating device has detected a fire condition. This is the highest priority signal:
- Red indicator on the panel and annunciator
- Continuous audible tone at the panel
- Activates all notification appliances (horns, strobes, speakers)
- Transmits alarm to the monitoring station
- Latches - remains active until manually reset
Trouble Signals
A trouble signal indicates a fault in the fire alarm system itself:
- Yellow indicator on the panel
- Pulsing audible tone (can be silenced, but LED remains)
- Common causes: open circuit, ground fault, power failure, communication loss
- Does not activate notification appliances
- Transmits trouble to the monitoring station
Supervisory Signals
A supervisory signal indicates an abnormal condition that could impair fire protection but is not a system fault:
- Yellow indicator (distinct from trouble)
- Common causes: sprinkler valve tamper, low air pressure, high/low temperature
- Does not activate notification appliances
- Transmits supervisory signal to the monitoring station
Exam Tip
Alarm = red, continuous. Trouble = yellow, pulsing. Supervisory = yellow, distinct. Only alarm signals activate notification appliances and initiate evacuation.
Fire alarm panels produce three signal types: alarm (red, continuous, activates NACs), trouble (yellow, pulsing, indicates system fault), and supervisory (yellow, distinct, indicates impaired protection). Only alarm signals trigger evacuation.