![]() It actually makes us look good, that the contractor can only find one thing we've "overdesigned" and it doesn't amount to anything. In my opinion, the minimum backfill cover for a concrete duct bank will be as per Table 300.50 column 2 and a minimum 2 concrete it is required above the conduit see b note.The duct bank shown in Figure 310.60 is provided with 3.5 concrete above the conduit if the duct size will be 4 only. So we laugh, and say put it in per design. ![]() So we have them quantify the amount the owner will save, and it invariably comes out to $5000 or $10,000. Side note: Whenever we have a VE (Value Engineering) phase on a project, the first thing the contractor wants to eliminate is duct bank reinforcing. There's no real design, but I have used the reinforcing to span the duct bank over a temporary trench. They're reinforced with #4's around the perimeter at 12 inch spacing and #4 ties at 24 inch centers. There's a lot of casual concrete (waste concrete, thrust blocks, foundation extensions, etc.), but if the backhoe operator sees red, he's been warned. There's a lot of reasons that don't hold up to close examination, but bottom line is, that if you're in a water or wastewater treatment facility, you're likely to be digging a trench through it or a hole into it. Underground concrete encased electric conduit duct banks shall consist of Type DB-60 or schedule 40 polyvinyl chloride (PVC) conduit rated for 90☌ cable and meeting NEMA Standard TC-6 and ASTM F-512 for underground applications. The post mentioned that there were spare ducts in the duct banks so I used table B310.6 and Figure B310. Client is demanding removal of this on the drawings. Re: Concrete encasement for duct banks Charlie I agree with you statement regarding using Annex B for cable ratings. I specified concrete encased rebar reinforced duct bank. Examples shown are for concrete encased reinforced duct banks, but the same principals apply to nonreinforced and / or encased. Multiple duct banks running around in parking lot with heavy truck traffic for deliveries and pickups. By prebuilding cages with rebar and conduit preinstalled, countless hours can be saved on the jobsite. If needed TCH can do road crossings in house using directional drilling to install a steel casing to have ductbank route inside.We reinforce electrical duct banks and require them to be red. Duct banks present an excellent prefab opportunity. TCH installs rebar enforced concrete encased duct banks for Centerpoint, ATT, Entergy and other energy/data suppliers turn key From PVC to Galvanized rigid conduit we can put it in the ground. From small to large ductbanks, TCH can handle your underground needs. We take pride in our ability to work on any size project. Calculates the duct bank size based on the quantity of conduits, the size and type of conduit. This consolidation allows property owners to upgrade or repair existing wiring without undergoing lengthy excavation projects. Existing 34.5kV and 5kV duct banks on site are all concrete encased so plan was to follow-suit with new installation but was also interested in common approaches for applying each. If counts change, you can re-calculate as many times necessary. After switches, light fixtures, convenience receptacles and occupancy sensors have been counted, simply enter the totals into AutoBranch. Bundling cables with a duct bank also streamlines future construction projects because the cables are consolidated and bundled to create a clear passageway. Whether it's a 50,000 job or 5,000,000 job, AutoBranch calculates a complete priced and labored bill of material in seconds. Duct banks not only protect the enclosed cables from damage, but they also consolidate and conceal the building’s series of wires. Dirt and concrete surrounding a conduit will definitely reduce the ability of heat to dissipate from the wires inside a conduit. Duct banks are typically installed underground for large buildings that require substantial wiring. A duct bank refers to a group of electrical conduits that provide pathways and protection for electrical wiring.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |