Method Statement For Installation Of Cable Tray Or Trunking

Electrical Engineers seldom show interest acquiring knowledge and experience on cable tray installations. Most of them think it's a concern of mechanical fabricators to be taken care of it. A proper and professional way of cable tray installation requires good involvement and coordination of people from both electrical and mechanical disciplines. If cable tray system has been installed appropriately in a project, following advantages can be counted:

  • Cable Tray system enhances safety of electrical wiring system.
  • Cable tray installation provides dependability in any circumstances.
  • Cable Tray system saves space, materials, labor, time and cost.
  • Maintenance and extension of cable tray installation are easier than any other wiring system.

Hence, electrical installation of a project must give high priority to adopt properly evaluated cable tray wiring system if aesthetic impact is low. This article explains how to make a typical method statement for cable tray or trunking installation for a building project.

Method of Clean Earthing or Grounding in Electrical System

Clean earth grounding or low noise earth shall be provided as required, to ensure that the level of induced or conducted interference from external sources, including the facility power grounding system, does not produce incidence of malfunction of the equipment, which is unacceptable for the operating system. The electronics systems must be protected by providing a network path having low impedance for interconnecting its equipment.

Proper routing, zoning and shielding of the cables / earth wires are important and must serve the purpose of preventing sources of electrical disturbances from the operation of electrical equipment.

Earthing or Grounding Method For Transformer Substation

MV switchgear and MV cables are to have separate main earthing bar connected to framework or earth bar of each item by insulated conductor and the earth-electrode by 2 insulated earthing conductors, one at each end of bar, via testing joints. Earthing conductor is to be minimum 150 mm2.

Lighting Distribution Boards (LDB) In Electrical Construction Works

Lighting Distribution Boards (LDB) are an integral and essential part of every building project and it must be designed, manufactured and installed all in accordance with the safety standards. In most of the cases it operates a layman wherein others operate dedicated or trained person. This article explains what are the essential standards, parts, frame to be applied for manufacturing and installation of lighting distribution boards in a quality building project.

Electrical Earthing or Grounding Electrode Design for Building Construction

Earthing or Grounding Electrode for an effective and reliable electrical earthing system requires proper survey and analysis of project location, type of structures installed and electrical / electronic equipment used in the entire system. The design calculation of the earth electrode systems shall be based on the approved earth resistivity data and the system's fault currents and their duration.

Typical Mounting Details 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. Conduit end to be taken out of the wall above false ceiling to allow the Firetuff cable to be clipped on soffit of the slab.

Drawing below shows how to install Manual call point break glass along with a sounder

In this typical drawing, manual call point break glass unit has been shown as concealed  and the rest  are surface installed in the false ceiling. Sounder has been mounted on ceiling but can also be mounted on wall visibly as per the project specification.

High Voltage and Low Voltage Power Cables In Electrical Construction

This article explains electrical power cables used in construction works complete with supply, installation, testing and commissioning of High Voltage (HV) and Low Voltage (LV) cables. All cables shall conform to standards of IS 7098-1973, IS 1554-1976 and wiring cables to IS 694-1977 however, contractor shall comply with the latest or superseded versions of IS/BIS to be used for the complete work.

Fire Alarm System In Electrical Construction Works

Fire Alarm System installation work covered by this section of the specifications includes the furnishing of all labor, equipment, materials, and performance of all operations in connection with the whole Fire Alarm System as shown on the drawings and as herein specified. The requirements of the conditions of the Contract, Supplementary Conditions and General Requirements apply to the work specified in this section.

Quality Plan for Construction Projects

It is essential that services and systems in a building construction contract work are provided to conform to the requirements of the customer, and that the activities be effected as economically as practical. The achievement of these objectives is facilitated by setting up working procedures and practices, which collectively provide a “Work Efficient”, yet controlled operating environment. It is the purpose of this Construction Quality Plan to give instruction to personnel, on the implementation of the company system such that the above objectives are accomplished. Documentation specific to the project will be provided to ensure full compliance with the particular requirements of the contract.

Method of Electrical Earthing And Bonding Multicore Cables

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. Where earth strip is buried or laid in positions in which there is danger of corrosion it shall be provided with a corrosion-proof serving of extruded thermo-plastic or self-adhesive PVC tape which for short lengths may be hand applied on Site.

Testing and Commissioning In Electrical Construction Works

At the completion of the electrical installation works, the entire installation shall be subject to the test before final placing in service under the full responsibility of the contractor. Unless Otherwise specifically called for all tests shall be carried out in conformity with IEE regulations. Contractor shall coordinate with the Client and the Supervising Engineer to get electricity from the local supply authority before starting of testing and commissioning.

Definitions of Electrical Earthing / Grounding Terms

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.

Requirements of Diesel Genset Plant in Building Services

Modern Buildings essentially implement the needs of Diesel Powered Electricity Generation Plant. It would become an integral part of the building the day building occupied by its tenants. Here we look into what are the objectives, specifications, services to be considered for functioning complete Diesel Powered Electricity Generation Plant installed in a commercial Building.