Setting requirements and cabling scheme for the five-party intercom system of hotel elevators
I am Ethan Liu, an elevator specialist. The five-party intercom system for hotel elevators is a key element in ensuring elevator riding safety and meeting special equipment regulatory and fire acceptance requirements. Its installation requirements and wiring scheme directly affect emergency response efficiency and system reliability. Based on my years of experience in hotel projects (including five-star hotels, resorts, etc.), this issue is often overlooked in design, but once a fault occurs, it can cause serious safety hazards and compliance risks.
Installation Requirements
According to Clause 14.2.1.3 of GB 7588-2003 "Safety Rules for the Construction and Installation of Electric Lifts" and Item 8.7 of Annex A of TSG T7001-2009 "Regulation for Lift Supervisory Inspection and Periodical Inspection—Traction and Positive Drive Lift", the five-party intercom system must meet the following core requirements:
1. Communication parties: Two-way communication must be achieved among the car, car top, pit, machine room (or control cabinet), and duty room (or monitoring center). In hotel projects, the duty room is usually located in the fire control room or security center.
2. Call quality: Calls should be clear and uninterrupted, with an automatic hang-up function. According to Clause 4.5.3 of GB/T 10060-2011 "Code for Acceptance of Electric Lifts Installation", the intercom system must still work normally when the elevator is powered off or faulty; therefore, independent power supply (such as UPS or battery) must be used, with a continuous power supply duration of no less than 30 minutes (refer to Clause 7.5.2 of GB 50116-2013 "Code for Design of Automatic Fire Alarm System").
3. Emergency trigger: There should be a clearly marked "emergency call" button inside the car. Pressing it should automatically connect to the duty room, and at the same time there should be an indicator light or audible prompt inside the car confirming that the call has been established. In hotel scenarios, it is recommended to integrate it into the elevator control panel to avoid accidental activation.
4. Redundancy and backup: According to GB/T 31094-2014 "Emergency Call System for Electric Lifts", the system should use wired or wireless means, but wireless must meet anti-interference requirements. In hotel projects, I usually recommend wired as the primary means and wireless as supplementary to ensure signal stability.
Wiring Scheme
Based on Clause 4.5.4 of GB 50310-2002 "Code for Acceptance of Construction Quality of Elevator Engineering" and Section 14.9 of GB 50198-2011 "Code for Design of Electrical Engineering for Civil Buildings", the following key points should be considered for wiring:
1. Cable selection: Use shielded twisted pair (such as RVVP 2×0.75mm² or 4×0.5mm²) to reduce electromagnetic interference. If the distance exceeds 500 meters, repeaters or fiber optics should be added. The environment inside hotel elevator shafts is complex, and cables must be flame-retardant (in accordance with GB/T 19666-2019).
2. Wiring routes:
- Vertical wiring: Install independent metal trunking or conduit along the elevator shaft wall, avoiding sharing the same trunking with power cables (such as 380V power lines), with a spacing of at least 300mm (refer to Clause 7.6.8 of GB 50054-2011 "Code for Design of Low Voltage Distribution").
- Horizontal wiring: Route from the machine room or control cabinet to the duty room, preferably through cable trays or above the ceiling, and reserve 20% spare capacity for future maintenance.
4. Grounding and lightning protection: According to GB 50057-2010 "Code for Design Protection of Structures Against Lightning", the system must have equipotential grounding, with a grounding resistance of ≤4Ω. In hotel projects, I once encountered a seaside project where a lightning strike paralyzed the system, which was later solved by adding surge protective devices (SPD).
Practical Engineering Case
I once participated in a five-star hotel project (30 floors, 6 passenger elevators). The initial design used wireless five-party intercom, but during trial operation, calls were intermittent due to WiFi signal interference in the hotel. Later, in accordance with the requirements of GB/T 31094-2014, the scheme was changed to wired: RVVP 4×0.75mm² shielded cable was laid in the shaft, routed vertically along metal trunking, and one UPS (45-minute backup) was installed in each of the machine room and duty room. During acceptance, power failure and fault scenarios were simulated; calls were clear and recovered automatically, and the system ultimately passed the inspection by the special inspection institute. In addition, a waterproof junction box (IP65) was added in the pit to prevent faults caused by humid environments.
Summary
The five-party intercom system for hotel elevators must meet the communication party, independent power supply, and call quality requirements of GB 7588 and TSG T7001. The wiring scheme should use shielded cables, independent routes, and proper grounding and lightning protection. In actual projects, it is recommended to use wired as the primary means and wireless as supplementary, and to reserve UPS capacity and redundant cables. The above are reference opinions. The actual project situation still needs further comprehensive evaluation and implementation in combination with specific operating conditions, site conditions, and other factors.