Electrical Installation

Typical Installation Details Of Floor / Wall Mounted Electrical SMDB

Floor mounted electrical Sub-Main Distribution Board (SMDB)
Electrical Sub-Main Distribution Boards (SMDB) are the integral part of Electrical LV Power distribution network in the end user premises of a medium and large scale projects. SMDB acts as a mediator between Main Distribution Board (MDB) and Final Distribution Boards (FDB) that serves approximately 100A to 400A load range. The drawings given here shows how to install:

Typical Details For Cable Tray Installation And Support System

Typical Detail Showing Cable Tray Crossing Building Expansion Joints
Below drawing shows how to install cable tray and its support system. This cable tray support system drawing has Isometric view and cross-sectional view. Following are the steps to be done for laying cables on wall mounted cable tray: Install cable tray support using a pre-fabricated flange or GI channel. The size, length and intervals of the support to be as per the specification, standards, number of cables, and size of the cable.

Automatic Transfer Switch (ATS) OR Automatic Mains Failure (AMF) Panel

Automatic Transfer Switch (ATS) OR Automatic Mains Failure (AMF) Panel

Reliable electrical power becomes one of the most wanted factor in modern world industry where operation should be uninterruptible and maximize the cycle of operation, output quality and to avoid losses and damages. Here we are talking about Automatic Transfer Switches (ATS) also known as Automatic Mains Failure (AMF) panel to cater uninterrupted power supply from Mains or backup sources like Diesel gen-set, static ups etc.

Master Antenna TV System (MATV) In Electrical Construction Works

MATV System
Master Antenna Television or MATV means many TV connection outlets from one Master antenna control system. Usually high-rise apartment houses, hotels, schools and cluster based residential area utilizes this kind of TV distribution network. It may or may not include FM radio so that one outlet can receive both TV and FM reception. The scope of this section covers the design, supply, installation, testing and commissioning of Master Antenna TV System, for the reception and distribution of television broadcast signals.

Method of Earthing or Grounding for Diesel Generator Plant

Eletcric Generator (Image Credit: www.cummins.com)

Earthing or Grounding of Diesel Generator Plant is important to ensure correct operation of the plant and safety of the people who work over there. Generator neutral (star point) is to be connected by insulated earthing conductor through the neutral earthing link or device to main earthing bar. Neutral earthing conductor is to be suitably sized to carry maximum earth fault current for time it takes the system protection to operate with final conductor temperature not exceeding 160 deg. C, but not less than 30 mm2 per 100 kVA of generator rating, with a minimum of 50 mm2. All emergency power diesel gensets including portable gensets to be connected to grounding conductor.

Guidelines for Installation of Emergency Power Diesel Generating Set

Emergency Power Diesel Generating Set (Image Credit: www.cummins.com)

We often depends Diesel Electrical Genset as emergency power system due to mains failure. As a professional, the installation of diesel electrical power generator should be as per the clients requirement and to be inline with the authoritative norms and standards. Safety, security, convenience, future expansions etc are to be considered and co-ordinated before start detailing of the genset's installation. The generator should be as close to the main change-over board as possible. In cases like Textile Mills, where there is fear of smoke affecting the quality of the yarn etc., generators may be located away from the Plant / Department.

Construction Specification For Electrical Busbar Trunking (Bus Duct) System

Busbar Trunking System
Busbar Trunking System (BBT) in electrical construction, uses to transporting electrical power to a shorter distance but many utilization point, say, within the building or a compound of facilities. Though cables can also be used in these areas, their economic impact would be high if compared to the effective Busbar Trunking System. It will help us to tap power directly from where we want it to be and make utilize to the service point.

Typical Mounting Details Of Fire Alarm Detectors

Typical Mounting Detail Of Fire Alarm Detectors mounted on false ceiling
These typical drawings show how to install smoke detectors and heat detectors used in Fire Alarm system on false ceiling. The installation shall be as per the relevant section in the contract specification and drawing has the following major points: Smoke detector mounted on false ceiling with the help of loop in box; Firetuff or equivalent cable run under the RCC slab clipped to the soffit; Cable size shall be 2 core 1.5 sq. mm copper; Cable has to be looped to the detector and tied as shown in the drawing.

Typical Mounting Details Of Fire Alarm Break Glass Manual Call Point

Typical Mounting Detail Of Fire Alarm Break Glass Manual Call Point

These drawings show how to install Fire Alarm Break Glass (BG) or Manual Call Point (MCP) on walls. It has to be mounted on back box installed in the wall. This box (embedded or exposed as specified in the concerned section of the specification) has to be connected through GI / PVC conduit that will have the Firetuff or equivalent cable to be looped for other detectors.

Indoor MV Distribution Panel Boards In Electrical Construction Works

MV Distribution Panel Boards In Electrical Construction Works
Building projects requires MV Distribution Panel-boards for distribution of power to each utilities. A good electrical distribution network will have proper design, right components, and future load provisions. Space utilization will also be an important factor for maintenance and handling of the equipments. Here we look into what are the features required for design, manufacture, install a MV Distribution panel board including its BIS (IS) standards that serving building projects.

Medium Voltage Distribution System In Electrical Construction

Specification for Medium Voltage Distribution System In Electrical Construction Contract Works
The work included within this section is for the supply, connection, testing and commissioning of 13.8 KV switch gears, cables, package sub station and all the related accessories necessary for the proper operation of the system as shown and described on drawings, bill of quantity and herein. The contractor shall coordinate with the other services (trades) involved in the project to insure that the foundation, are suitable for the equipment to be installed.

Electrodes for Earthing or Grounding System in Building Construction

Electrical Earth Pit or Grounding Pit

A. Ground Rod:

16 mm diameter stainless steel. Driving head is to be high strength steel. Couplings are to be long length silicon bronze, internally threaded. Threads are to be rolled onto rod to ensure uniform layers of copper and strength. Earth rod is to be complete with non-corrosive couplings, head and bolted connector of sufficient size, and number of bolted clamps to connect all cables terminated thereto.

Public Address System In Electrical Construction Contract

Public Address System In Electrical Construction Contract
The contractor shall supply, installation, test and commission a public address system consisting of power amplifier, mixer power amplifier, microphone module, paging console, cabinet rack, conduits and wiring and all the necessary equipment required by the system shown and described on drawings, bill of quantities and hereinafter.

Connector Products And Accessories for Electrical Earthing or Grounding System

Electrical Earthing Connector Products Typical Methods
Connector Products And Accessories for Electrical Earthing or Grounding System shall be as follows: Copper or copper alloy, purpose made, of approved design, compatible with points of connection, and of adequate cross-section and current carrying capacity. Connections to metallic structures for earthing conductors and bonding conductors between electrically separate parts of a structure shall be either by direct exothermic welding or by bolting using a stud welded to the structure.

Conduit Wiring In Electrical Construction Contract Works

Electrical Power Layout Conduit Installation

Scope of Work of this this sample specification covers the supply, installation, testing and commissioning of all wiring materials for power and lighting in concealed and/or surface conduits.

1. Applicable Standards

The conduits shall conform to IS 9537 I & II  or equivalent standards. Switches, Plug Sockets shall conform to IS 3854 and IS 4615, however, contractor shall comply with the latest or superseded versions of IS/BIS to be used for the complete work.

Definitions of Electrical Earthing / Grounding Terms

Electrical Earth Electrode

In electrical projects, both construction as well as maintenance, the following terms used on the Drawings, Specifications and in the actual Work site are equivalent and may be used interchangeably: "earth" and "ground"; "earthing" and "grounding". Besides, this article tries to rectify misinterpretation of some important terms often used by people involved in the electrical earthing / grounding work.

Low Voltage (LV) Switchgears in Electrical Construction Works

Low Voltage Switchgears in Electrical Construction Works

Low Voltage Switchgear are familiar to every people since they are the controlling mediators between low voltage utilities and equipment with human beings. Be it a common home DB or an isolator or control centres, they all are being manufactured to use untrained people ie., common people. The scope of works shall cover the supply installation, testing and commissioning of main and sub-distribution boards, panel boards, fusible safety switches, circuit breakers etc. Associated minor building works require for the erection of the distribution boards and panels shall be included in the scope of work.


Method of Electrical Earthing And Bonding Multicore Cables

Multicore Cable showing details of each parts

The metallic sheath and armour of multicore cables shall be bonded together and earthed. Cable earthing conductors shall be copper strip with appropriate section laid in formed cable trenches or ducts, or fixed to walls, concrete or steel work, by means of clamps or claw type cleats, appropriately secured into suitable wall plugs or tapped holes. The spacing of fixings shall not be greater than 1 m.

Method of Earthing or Grounding Of MDB, Panel Boards, Lighting And Wiring Installations

Method of Earthing or Grounding Of MDB, Panel Boards, Lighting And Wiring Installations
Main earthing bar is to be provided in main distribution room and connected to earth electrode by 2 insulated conductors (minimum 150 mm2) via testing joints. Earthing bars of main distribution boards are to be connected, by insulated earthing conductor, directly to main earthing bar at main distribution room.


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