Notification Appliance Test Mode for Reduced Noise Disturbance
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Solution Overview
Problem
Testing of audible and visible notification appliances on the Notification Appliance Circuit (NAC) in fire systems poses challenges due to the need to ensure devices function properly without disturbing building occupants, especially in occupied buildings where noise from simultaneous activation is disruptive and testing is often impractical.
Innovation Solution
A method where the NAC circuit is placed into a test state by sending specific pulses on power lines, allowing individual devices to be tested independently with reduced sound and light intensity using a magnet, enabling multiple testers to conduct tests simultaneously without widespread disturbance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If all devices on the NAC circuit are activated simultaneously for testing, then the functionality of all devices can be validated at once, but the noise level increases significantly causing disturbance to building occupants
Solution Approach 1:
The patent divides the testing process into individual device tests rather than simultaneous activation. Each notification appliance can be tested independently by activating it one at a time through the interface, allowing thorough validation of all devices while limiting noise exposure at any given moment.
Solution Approach 2:
The system enables sequential activation of individual devices for testing purposes. The interface allows periodic activation of single appliances rather than continuous or simultaneous activation of all devices, thereby controlling noise levels while maintaining testing effectiveness.
2Ease of operation
If testing is conducted in occupied buildings, then testing can be performed during normal operations, but employees or patients must step outside or tolerate noise disruption
Solution Approach 1:
By enabling individual device testing rather than system-wide activation, the patent allows testing to occur while occupants remain in their locations. Each device can be tested independently without requiring employees to leave or patients to be moved, thus maintaining operational accessibility while minimizing disruption.
3Object-affected harmful factors
If the NAC circuit is placed in test state with individual device activation, then noise disturbance is minimized, but the testing process becomes more time-consuming
Solution Approach 1:
The system facilitates rapid sequential activation of individual devices through the interface. While testing occurs one device at a time, the periodic nature of activation allows for efficient progression through the testing list, balancing reduced noise exposure with acceptable testing time through streamlined operation.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables thorough testing of all devices within the system without causing significant disruption, reducing test time and accommodating occupied buildings by allowing testing to occur without major interruptions, ensuring devices are functional while minimizing noise impact on occupants.
Implementation Method 1
The person conducting the test would go to each device independently and hold a magnet up to the device in order to enable that particular device to flash and/or sound
Data Source
AI summary
An output device emits alarm indicating light and sound at predetermined levels when activated. The device enters a test mode in response to received test mode indicating control signals. When the device is in the test mode and a local test initiating control signal is received, audio and/or visual outputs are emitted at a level reduced from the alarm indicating output levels to test those outputs.