Power supply and control requirements for hotel fire shutter doors and smoke exhaust fans
I am electrical expert (James Li), specializing in power supply and distribution and fire protection electrical system design. The power distribution and control of hotel fire shutter doors and smoke exhaust fans you mentioned are core aspects of fire protection electrical system design, directly related to the success or failure of personnel evacuation and firefighting rescue during a fire. According to the Code for Fire Protection Design of Buildings GB 50016-2014 (2018 Edition) and the Code for Design of Automatic Fire Alarm Systems GB 50116-2013, these devices must ensure power supply reliability and control logic accuracy. The following is a detailed analysis from three aspects: power distribution requirements, control logic, and engineering practice.
1. Power Distribution Requirements: Dual Power Sources and End-of-Line Switching
Standard Reference:
- Article 3.0.2 of the Code for Design of Power Supply and Distribution Systems GB 50052-2009 clearly specifies that fire protection electrical equipment (including fire shutter doors and smoke exhaust fans) belongs to Grade I loads and should be supplied by dual power sources, with automatic transfer devices installed at the final-level distribution box.
- Article 10.1.8 of the Code for Fire Protection Design of Buildings GB 50016-2014 emphasizes that fire protection distribution lines should meet the requirement of continuous power supply during a fire, typically using mineral-insulated cables (such as BTTZ or NG-A type) or flame-retardant fire-resistant cables (such as NH-YJV).
In hotel projects, I often separate fire shutter doors and smoke exhaust fans from ordinary load circuits, drawing two dedicated power supplies from different busbar sections of the substation. For example, in the design of a five-star hotel (approximately 300 guest rooms), I installed dual power transfer cabinets (ATSE) in the fire pump room and smoke exhaust fan room respectively, with a transfer time of ≤0.5 seconds, ensuring that the backup power source (diesel generator) automatically engages when the mains supply is interrupted. Note that the fire shutter distribution box is usually located near the shutter, and the smoke exhaust fan distribution box is located inside the machine room, avoiding excessive voltage drop caused by long lines.
Case:
In a hotel project in Suzhou, because the fire shutter doors shared a distribution box with ordinary lighting, the fire department cited a violation during acceptance inspection. After rectification, we laid dedicated NH-YJV-5×4mm² cables for each shutter and added dual power transfer boxes, ultimately passing acceptance.
2. Control Requirements: Linkage Logic and Manual Priority
Standard Reference:
- Article 4.5.1 of the Code for Design of Automatic Fire Alarm Systems GB 50116-2013 specifies that the descent of fire shutter doors should be triggered by the "AND" logic of two independent fire detectors (such as smoke and heat detectors) within the fire compartment, and manual control buttons must be provided.
- Article 4.5.2 requires that smoke exhaust fans should be started by the linkage controller after a fire alarm, and manual direct control devices (hard-wired control) should be installed in the fire control room.
- Fire Shutter Doors:
- Shutters used only for fire compartmentation: upon receiving a fire signal, descend to the bottom in one step (such as atrium shutters in hotels).
- Shutters used for evacuation routes (such as corridors): first descend to 1.8m above the ground, then descend to the bottom after personnel evacuation is complete. I typically use smoke detectors to trigger the first-step descent and heat detectors to trigger the second step.
- The control circuit needs to be equipped with limit switches, overload protection, and emergency stop buttons to prevent mechanical jamming.
- Smoke Exhaust Fans:
- Controlled by the fire alarm controller through modules, with the start signal coming from detectors or manual alarm buttons in the corresponding smoke control zone.
- A 280℃ smoke exhaust fire damper should be installed; when the flue gas temperature reaches 280℃, the damper closes and interlocks to stop the fan (according to Article 4.5.5 of GB 50116).
In control box design, I adhere to the "manual priority" principle—even if automatic control fails, firefighters can start the fan through on-site buttons or remote control from the fire control room. For example, in a hotel project in Shenzhen, we configured a multi-wire control panel (hard-wired direct start) for each smoke exhaust fan and reserved backup circuits to ensure redundancy.
Case:
During commissioning at a hotel in Hangzhou, the smoke exhaust fan could not start automatically due to a loose wiring connection in the control module. We immediately activated hard-wired manual control and promptly resolved the fault. Afterward, I required all modules in control boxes to use anti-loosening terminals and regular testing of linkage logic.
3. Construction and O&M Precautions
- Line Routing: Fire shutter door and smoke exhaust fan lines should be run in metal conduits or enclosed trunking and coated with fireproof paint (according to Article 10.1.10 of GB 50016). In a certain project, I found that the cable tray lacked firestop sealing and immediately required it to be supplemented.
- Grounding Protection: All equipment enclosures must be reliably grounded, with grounding resistance ≤1Ω (according to Article 2.2.4 of GB 50054-2011).
- Regular Testing: In hotel O&M, it is recommended to simulate a linkage test once a month to check the shutter descent speed and fan air volume (for example, the smoke exhaust fan air volume should be ≥7200m³/h, according to the Technical Standard for Smoke Control and Exhaust Systems in Buildings GB 51251-2017).
The above are reference opinions. The actual project situation still needs further comprehensive evaluation and implementation in combination with specific working conditions, on-site conditions, and other factors.