Can electrical risers and low-voltage/telecom risers in a hotel be combined? What are the code requirements?
I am electrical expert James Li. The issue you raised is very critical in hotel electrical system design, as it directly affects power supply safety, system reliability, and later operation and maintenance efficiency. Based on my years of engineering experience, the question of combining electrical shafts and extra-low-voltage (ELV) shafts must be strictly differentiated and cannot be generalized, because strong-current and ELV systems differ fundamentally in electromagnetic compatibility, fire compartmentation, and maintenance convenience.
First, the core standard reference comes from the Code for Electrical Design of Civil Buildings GB 51348-2019. Article 8.1.4 of this standard clearly stipulates: "Electrical shafts should not be shared with elevator shafts, pipe shafts, etc.; strong-current and ELV lines should be provided with separate shafts, and when conditions are restricted and they must be combined, strong-current and ELV lines should be arranged on opposite sides of the shaft or isolation measures should be taken." In addition, Article 6.2.9 of the Code for Fire Protection Design of Buildings GB 50016-2014 (2018 edition) requires that vertical shafts such as cable shafts and pipe shafts should be provided independently, and inspection doors on shaft walls should use Class C fire doors. The core logic of these provisions is: strong-current lines (such as 380V/220V power cables) generate electromagnetic fields that interfere with ELV signals (such as structured cabling, fire alarm, building automation, etc.); at the same time, strong-current line faults may cause fire or electric shock risks, affecting the safety of ELV equipment.
In actual projects, I strongly recommend that hotel projects give priority to separate strong-current and ELV shafts. For example, I once participated in a five-star hotel project where, in the initial design, due to space constraints, the strong-current and ELV cable trays shared a 2 m × 1.5 m shaft separated only by metal partitions. However, during the commissioning stage, bus signals of the fire alarm system frequently produced false alarms, and investigation found that this was caused by harmonic interference from strong-current cables. Ultimately, new openings had to be made to add an independent ELV shaft, increasing cost and schedule. Therefore, from the perspective of system reliability, separate shafts are the best practice.
If sharing is unavoidable (for example, in existing building renovation or when space is extremely limited), the following measures must be taken:
1. **Physical isolation**: The spacing between strong-current and ELV cable trays shall be no less than 300 mm, or metal partitions shall be used for complete separation, with the partitions well grounded.
2. **Zoned arrangement**: Strong-current lines shall be arranged on one side of the shaft and ELV lines on the other side to avoid crossed routing.
3. **Firestop sealing**: At each floor slab in the shaft, firestop materials (such as firestop putty and firestop pillows) shall be used for tight sealing to meet a fire resistance rating of not less than 1 hour.
4. **Grounding system**: A dedicated grounding main (usually -40×4 galvanized flat steel) shall be provided in the shaft and reliably connected to the main equipotential bonding terminal to ensure equipotentiality.
In addition, with reference to Article 7.0.1 of the Code for Engineering Design of Generic Cabling Systems GB 50311-2016, ELV shafts should be kept away from strong electromagnetic interference sources, which further supports the necessity of separate shafts.
Summary: In principle, hotel electrical shafts and ELV shafts should be provided separately, which is the optimal choice for ensuring system reliability and safety. If sharing is unavoidable due to condition constraints, physical isolation, firestop sealing, and equipotential grounding measures must be strictly implemented, and design review and acceptance confirmation are required.
The above are reference opinions. The actual project conditions still need to be further comprehensively evaluated and implemented in combination with specific operating conditions, site conditions, and other factors.