“Seal all underground conduits to prevent gases and water from entering the building or other MHs via the ductbank.” DIN 18322:2019-09 3.7.2: “All conduits shall be plugged to restrict infiltration of gas, water, and vermin.” BICSI-TDMM: “Ducts shall be sealed to resist liquid and gas infiltration at all maintenance holes and building entrance point locations.” TIA-758-B Standard 5.4.2.3: The installation of empty (spare) microducts that do not contain microcables, should also be sealed in the cable chamber, inside the building.” TIA-758-B Standard 5.1.1.2.8: Microcable should be sealed to the microduct both in the cable chamber adjacent to the building as well as inside the building. “It is mandatory to use pipe – microduct sealing elements (sealing between pipe and microducts), in order to ensure … the seal against the entry of liquids and gases … to protect the branch of microducts.
Cables entering or exiting a manhole or hand-hole have to be sealed.” Related Content: Duct Seals Prevent Ruinous Water Damage Therefore, manholes and hand-holes are required to be water tight. Water can enter manholes, hand-holes and cable tunnels, which can cause telecommunication equipment to break down. Outside plant facilities are also damaged by floods. “… sealing the ends of the plastic tubes (at the manholes/pits of our underground infrastructure) with foam filler. The use of seals may be supplemented by gas-venting devices in order to minimize building up of positive gas pressures in the conduit.” ITU Rec. “The portion of a conduit installed through an exterior building wall, floor, or roof shall have seals inside the conduit and external seals on the outside surface of the conduit at the point of entry to the building intended to limit the likelihood of the entrance of gas into the building. “A conduit seal shall be required in each conduit run leaving a Class 1, Division 2 location… and it shall be designed and installed to minimize the amount of gas or vapor within the portion of the conduit installed in the Division 2 location… Such seals shall not be required to be explosion proof…” NESC 322 (b)(4): “Where a raceway enters from an underground system, the end within the building shall be sealed with an identified compound so as to prevent the entrance of moisture or gases, or it shall be so arranged to prevent moisture from contacting live parts.” NEC 501.15 (B)(2) Conduit Seals, Class 1 Division 2: An explosion proof seal shall not be required for this purpose.” “Where portions of a raceway or sleeve are known to be subjected to different temperatures, and where condensation is known to be a problem, as in cold storage areas of buildings or where passing from the interior to the exterior of a building, the raceway or sleeve shall be filled with an approved material to prevent the circulation of warm air to a colder section of the raceway or sleeve. Sealants shall be identified for use with cable insulation, conductor insulation, bare conductor, shield, or other components.” Related Content: Sealing Conduits for Resilient Electrical and Telecommunication Systems Spare or unused raceways shall also be sealed.
“Conduits or raceways through which moisture may contact live parts shall be sealed or plugged at either or both ends. Sealants shall be identified for use with the cable insulation, shield, or other components.” NEC 300.5 (D)) G) Raceway Seals: “Where a service raceway enters a building or structure from an underground distribution system, it shall be sealed in accordance with 300.5(G). Sealants shall be identified for use with cable insulation, conductor insulation, bare conductor, shield, or other components.” NEC 230.8 Raceway Seal: “Where a raceway enters a building or structure from outside, it shall be sealed.
Let’s review the language in a sampling of pertinent electrical and communication industry codes from around the world: NEC 225.27 Raceway Seal: The infographic linked here and also found below, illustrates the need for duct seals and lists various governing standards.
0 kommentar(er)
