Wiring specifications for automatic fire alarm systems
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In the GB50116-2013 Code for Automatic Fire Alarm Systems, regarding integrated cabling, it is stipulated in \"11.1.3\" that when the power supply lines and transmission lines of automatic fire alarm systems are installed outdoors, they should be laid underground. ”Many people have the misconception that outdoor wiring can only be laid underground. If this understanding is correct, then must the alarm devices be buried underground to meet the regulatory requirements? Obviously, it was misunderstood one-sidedly. So how should the meaning of this passage be correctly interpreted? In my opinion, for outdoor wiring in chemical processing projects, tray systems are the primary design option; where it is not possible to use trays, and when the wiring distances are large and there are many cables, underground installation should be employed ； When the installation distance is short and the number of cables is small, they should be installed in pipes, with the power supply lines and the transmission lines either run separately or also installed in their own pipes. Since the issuance of the standard GB50116-2013, chemical projects have adopted this standard for underground installation, but the acceptance standard remains GB50166-2007; the content of the acceptance standard does not keep up with that of the design standard. If all current projects adopt buried installation methods, it will undoubtedly increase the difficulties in design and construction, as well as raise costs, thereby creating unnecessary challenges for the operation and maintenance of future projects. This is just my humble opinion; I hope it can serve as a starting point for further discussion
Building electrical engineering codes are not applicable to outdoor areas and cannot be cited.
The discussion topic originally came with guidelines, but I don’t know how they disappeared
We do have a project where the installation is intended to be underground, but this increases the difficulty of construction significantly. Can the main signal cable be installed overhead instead? Seek help from experts!
Cable trays cannot ensure safety; in the event of an accident that damages the cable tray, all monitoring and alarm systems will become disabled and will be unable to provide early warnings. That’s why they need to be buried! This isn’t difficult at all; the civil work should involve preparing the pipe shafts in advance and embedding cable conduits, so that wires can be installed later even in case of failures or additional requirements!