Earthing System For FTTH Cabinets and DPs - technopediasite-Ultimate Resource For Telecom Technical Support


Saturday, June 27, 2020

Earthing System For FTTH Cabinets and DPs

Earthing System  For FTTH Cabinets and DPs : In this article, I will discuss why required earthing for cabinets, DPs and manholes. Particular issues of earthing also come up in the FTTH project, which have to be completed. If we want to tell earthing in easy language, then we can say that by connecting a wire on the metal part of any metal machine or equipment, we connect it with earthing plate and earthing electrode, we call it earthing or grounding. For the earth plate or earthing electrode, we use a very thick wire with very low resistance.

It is not that only in the electrical sector, the need of the earthing is very important, in telecom too, there is a very special need for earthing, earthing is very big value, where there is some work related to electricity, earthing is definitely there. In telecom sector earthing required for Cabinets, DPs, Manhole, BTS tower, Cable vault.
Earthing System  For FTTH Cabinets and DPs
Earthing system in Telecom

Earthing Hardware

Earthing in the telecom sector requires certain hardware which will be discussed below. These are following earthing hardware-

➤Earthing Wire
➤Earthing Wire Connector
➤Earthing Strand
➤Earthing Rod Assembly
➤Moisture Barrier Clamp
➤Bonding Ribbon
➤Bonding Ribbon Wall Clamp
➤Connecting Clamp, Strand to Earth Rod.

These earthing hardware shall be used in the following earthing systems-

➥Cabinets and DPs earthing system for earthing terminal blocks and cables
➥Manhole earthing system for earthing cables
➥Cable vault earthing system for earthing cables.

Earthing Wire : A stranded copper wire, 3 mm in diameter, used with ring terminal-type wire connectors, to provide bonding facility between the cables’ aluminum moisture barrier and the earthing terminals.

Earthing Wire Connector : A ring terminal-type connector equipped with a female insulating sleeve for crimping the earthing wire end. Used to provide connection facility for earthing wires, terminal ground lugs and bonding clips.

Earthing Strand : Constructed of 7 galvanized steel wires, twisted together to form a strand. Used to electrically earth cabinets and distribution points (DPs).

Earthing Rod Assembly : An assembly of two 1-meter earthing rod sections, maybe solid or tubular, connected by a coupling spike, and provided with a clamp to connect the earthing rod to the earthing strand.

The assembly shall include:
➤pointed driven-end of the first rod with sufficient strength when driven through hard soil.
➤an impact cap to protect the driven-end of rods during impact with the hammer.

Moisture Barrier Clamp : Composed of two plates with interlocking barbs on inside mating faces. The lower plate shall have 5 mm diameter threaded stud, and the upper plate with a matching hole to fit onto the stud. Used to clip the cable’s aluminum moisture barrier for the connection of the earthing wire for bonding and earthing of the cables.

Bonding Ribbon : A flat, annealed, tinned copper strip attached onto the walls of manholes and cable vaults with the use of bonding ribbon wall clamps. In facet Bonding Ribbon used to provide a common electrical bonding facility for all cables and joints in manholes or cable vaults.

Bonding Ribbon Wall Clamp : A clamp made of high strength plastic material equipped with concrete nail. It is type of clamp and used for fixing bonding ribbon to walls of manholes and cable vaults.

Clamp, Connecting Earthing Strand to Earthing Rod : A galvanized steel clamp, oblong-shaped, equipped with one hexagonal head tightening screw to provide solid attachment of the earthing strand to earthing rod.

Earthing hardware Specification

The earthing hardware shall be designed and constructed as specified in below table-
Design Requirements for Earthing Hardware
Earthing Hardware Details

Types of Earthing

Earthing is usually done in two different ways. Now we will discuss about both types of earthing.

1. Pipe earthing
2. Plate earthing

Pipe Earthing

A 2.5-meter galvanized pipe is buried in a 3-meter pit in a pipe earthing. One end of the pipe is placed on the outer side of the ground, and coal, salt and black soil in the pit which is considered very good for earthing, all three are mixed and the pipe is buried.
Construction details of pipe earthing
Construction of Pipe Earthing

And on top of that a tank is made, in which the connector is placed, to which the earthing device is connected with the help of a nut bolt with the help of copper wire or cable, a water tap is placed in the tank. Sometimes water is carried into the ground during the summer days, which makes the earthing strong and good.

Plate Earthing

In plate earthing, a 2.5 * 2.5 ft galvanized plate is jointed with a copper wire or cable with a welding or nut bolt and buried in the ground. And the plate is buried in the pit with coal and salt soils.

And the carrier attached to it is taken out from the ground, a tank is made there, and from there the device is to be connected to the body of the earthing.

Apart from this, earthing is also connected with house wiring, because the same earthing is added to all the electrical appliances in the entire house, so that whenever our device is shortened body then the current reaches directly to the body of the appliance. It reaches the ground, and we are protected.