When an underground system is built, there can be areas where personnel entry is not required for installing or servicing electrical or communications wiring. Handholes, underground pull boxes, and underground boxes serve as space to assist the cable to pass through ducts smoothly, an underground pull boxes is a sort of.
Fiber Handholes
Fiber handholes are underground vaults that protect and allow access to the telecommunication network. Handholes are typically underground and installed at regular intervals along the length of the utility line for maintenance and management purposes. A handhole is a junction point for fiber cables and splicing enclosures. They are ubiquitous but unobtrusive in residential and commercial areas.
Handholes are typically made of composite or precast concrete, They are designed with knock-out holes or curable structures. They are usually rectangular and can range in size from a few inches to several feet.
Underground Pull Box
An underground pull box is a kind of cable vault deployed as a branching point for pulling, and storing fiber cables that leading to other handholes.
Underground pull boxes are typically made of composite, precast concrete, or plastic, An underground pull box is the assembly of a rectangular box with a composite cover, they are hex bolt fixed which makes it easy to access the cables for maintenance and deployment purposes.
Underground Boxes
Underground boxes are typically made of composite, sizes from several inches to one or two feet. Underground boxes are protective enclosures that allow access to FTTH fiber splicing, electrical wire connections, and irrigation water valves. They are also known as irrigation valve box, electrical splice boxes, and surface boxes. etc. They are installed on empty land that allows occasional traffic.
Handholes, underground pull boxes, and underground boxes provide access to underground utilities, such as fiber opic, electrical, water, and pipelines, for maintenance and access purposes. This section describes providing, adjusting, and removing pull boxes
Materials
(1) Furnish pull boxes made of corrugated pipe conforming to the material requirements with annular corrugations.
(2) Furnish non-conductive pull boxes and junction boxes from department approved product list. The contractor may field trim to customize pull box lengths.
(3) Furnish handhole frames and manhole covers. Use locking covers in pavement roadway locations.
(4) Furnish grounding lugs made of copper or stainless steel. Use stainless steel for mechanical connections to pull boxes and junction boxes.
Construction
(1) Provide pull boxes with manhole frames and solid lids. The contractor may extend pull boxes as theplans show using the same material as the pull box. Saw extensions parallel to the annular ring and clamp to the pull box using a band manufactured for this purpose. Excavate, place coarse aggregate drain material, and backfill as the plans show. Dispose of surplus or unsuitable material as specified requirements. Use covers stamped “TELECOM” for communications pull boxes or “ELECTRIC” for electrical utilities.
(2) Under the Junction Boxes bid items, provide junction boxes mounted and connected as the plans show. Grounding lugs are not required in junction boxes with less than 50 volt AC.
(3) Under the Adjusting Pull Boxes bid item, move existing pull boxes to grade level. Excavate, adjust subsurface components as required, and backfill as the plan details show. Dispose of surplus or unsuitable material as specified.(4) Under the Removing Pull Boxes bid item, excavate and remove existing pull boxes. Backfill with material similar to the surrounding material. Dispose of surplus or unsuitable material as specified.