Smoke Control Series – Part Two: System Integrity & Reliability

Ensuring the integrity and reliability of a smoke control system is paramount for life safety. Codes and standards governing these systems outline rigorous requirements to uphold their ongoing dependability. The International Building Code (IBC) and NFPA 92 Standard for Smoke Control Systems both detail what is required to be done and how the performance should operate. 

For instance, to guarantee the hardware’s integrity, codes often mandate that control panels be UL 864 listed for smoke control system equipment. This ensures they meet stringent standards akin to fire alarm systems, crucial for effective operation in smoke control applications. Note that a smoke control system is NOT a fire detection and emergency evacuation system.  They are two completely different systems; it just so happens that a fire alarm system will trigger the smoke control system to activate. The same is true for the building environmental control system, parts of the BAS are used for smoke control however these individual parts are distinctly used for smoke control within a building. 

Additionally, certain codes stipulate secondary power provision and enclosed wiring raceways for smoke control systems. This is because the power requirements, particularly for fan operation, surpass those of standard fire alarm systems. 

It’s essential to recognize that monitoring circuit integrity in smoke control systems differs significantly from fire alarm systems. This variance has led to confusion among those unfamiliar with smoke control systems, causing delays in obtaining Certificates of Occupancy. 

Fire alarm systems typically employ electrical supervision, monitoring circuit integrity through resistors and current levels. In contrast, smoke control systems utilize end-to-end verification, confirming circuit connectivity, power supply, and proper device activation. This method ensures functionality beyond mere signal transmission, verifying operational elements such as fan airflow and damper positions. The positive feedback from the mechanical equipment to turn on/off or open/close ensures that the system’s mechanical aspects are functioning correctly.  Should the commanded operation fail, the system will report and record the failure alerting on-site personnel to fix the fault. 

The distinction lies in their scope: electrical supervision focuses on circuit wiring integrity, while end-to-end verification extends to mechanical components like fan belts and damper linkages. Notably, NFPA 92 and the IBC mandate positive confirmation of activation, necessitating end-to-end verification even if electrical supervision is available. 

Despite their differences, both approaches aim to detect faults. Electrical supervision swiftly identifies wiring issues, while end-to-end verification detects faults in both wiring and mechanical equipment, albeit during activation. 

Moreover, dedicated smoke control equipment undergoes weekly self-tests per UL 864 and NFPA 92 requirements, detecting faults in wiring and mechanical components. Non-dedicated equipment, integrated into building or HVAC control systems, relies on regular usage and occupant feedback to verify operation. 

In summary, while neither electrical supervision nor end-to-end verification is perfect, it would be hard to argue that either approach is better at detecting fault conditions; they are simply two different approaches with the same goal in mind. Electrical supervision can point out within 200 seconds that a fault exists in the control circuit wiring, but it will never detect a broken fan belt, clogged air filter, loose actuator linkage, or other fault in the mechanical equipment that could completely compromise the smoke control system and prevent air from flowing or dampers from moving when needed. End-to-end verification can detect faults in the control wiring, lack of power to the controlled equipment, and faults in the mechanical equipment, but it can do so only when the equipment is activated.  

Detailed Examples of Electrical Supervision vs End-to-End Verification:

Prefabrication Options for Fan & Damper Field Integrations

Utilizing prefabricated solutions for the integration of devices in the field at each fan and damper location associated with the overall smoke control system will shorten the construction timeline and improve quality of the overall project. Efficiency is gained in design time, installation and pre-testing phases while final system commissioning time and delays are reduced. Code mandated inspection, testing and maintenance of the system also benefit over the longevity of the facility. 

Designed to each project’s functional needs, every solution is tailored to the device type it is integrating with in the field. Able to be fitted for high and low voltage connections, the overall design accommodates those details to comply with NEC (National Electrical Code) standards. Each solution is expertly assembled in a controlled environment by IPS certified technicians and properly documented for future reproduction on other projects. Once completed and quality checked, the prefabricated enclosures are packaged with unique identification labels then delivered to the customer ready for installation. 

To learn more about our smoke control and prefabrication capabilities please visit: https://www.1sae.com/panelvu-annunciators