Conditions Of Sub-Contract Agreement In Construction

Occasionally Main Contractor of the construction work depends sub-contractor for accomplishing some smaller or part of the project that may require specialized technical know-how and installation methods. In those cases Main contractor selects some sub-contractors who has capacity to achieve the task within the given time frame. Hence both of the parties, ie., Main contractor and Sub-contractor to be signed an agreement which protects both the parties' interest. Here is a sample for Conditions of Sub-contract Agreement in Construction Works.

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 For Metallic Fencing

Compound Demarcation or separations of compounds may use metallic fences sometimes for saving money or aesthetic reasons. Architects and owner of the project decide whether their property protected by compound wall or it needs only fencing. If fencing considered, most cases it will be metallic fence. In the electrical point of view and as a safety measure, metallic fence shall be separately earthed unless they come within 1.8 m of any equipment or structure above the surface of the ground, which is connected to the main earthing system. If the separation of 1.8 m cannot be obtained the fence shall be bonded to the earthing system. Here is how compound fences connecting to the earthing system.

Medium Voltage Cables (MV Cables) In Electrical Construction

The contractor shall supply, install, test and commission the 13.8 KV cable network as shown and indicated on the contract documents. Conductor sizes shall be metric as shown, conductor sizes with cross sectional areas smaller than specified will not be accepted. The cable installation shall include all trench work, sleeves, ducts, and all necessary fixings and cable terminations at both ends of the cable. The contractor shall supply and install cable marker posts to indicate the route of all underground cables. Markers shall be provided at every bend along the route and at sites of crossing roads or pipe lines.

Low Voltage (LV) Power Cables In Electrical Construction Works

The scope of work shall cover laying, connecting, testing and commissioning of low voltage power cables complete with all cable support, cable, cable trays, clamps and joints. Cables to be purchased from who regularly engaged in the manufacturer of electrical cable and wire products of the types and ratings required, whose products have been in satisfactory use in similar service not less than 5 years. The standard of the cables shall comply with National Electrical Manufacturers Association of local standards or any other approved.

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.

Typical Details For Cable Tray Installation And Support System

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:

  1. 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.
  2. Fix the cable tray as shown on the drawing.
  3. Lay the cable keeping the distance as per calculation.
  4. Tie the cable using cable tie and label the cables as required.

Construction Shop Drawings

Construction Shop drawings are the actual detail of all manufactured or fabricated items, indicate proper relation to adjoining work, amplify design details of equipment in proper relation to physical spaces in the structure, and incorporate minor changes of design or construction to suit actual conditions.

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.

Electrodes for Earthing or Grounding System in Building Construction

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.

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.

Methods of Installing External, Exterior and Outdoor Lighting System

Installation Methods of External, Exterior and Outdoor Lighting System includes lighting equipment luminaires, control gears, panel boards, poles, brackets, cabling, and allied minor civil works. All installations are to be carried out under strict supervision of qualified supervisors and engineers. If installation required heavy vehicles, extreme care has to be taken for preventing damages of lighting equipment, control gears and poles.

Importance of Fire Alarm System

Fire alarm systems have become increasingly sophisticated and functionally more capable and reliable in recent years. They are designed to fulfill two general requirements: protection of property and assets and protection of life. As a result of state and local codes, the life-safety aspect of fire protection has become a major factor in the last two decades.

Low Voltage (LV) 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.

Vacuum Interrupter (VI) for Vacuum Circuit Breakers (VCB)

Vacuum Interrupter (VI) are vacuum sealed-off devices incorporated in Vacuum Circuit Breakers (VCB) to cause interruption of fault currents in medium voltage electrical distribution systems. The contacts of the VI are pressed against each other under normal circuit conditions. In the event of a fault current, the VCB mechanism effects withdrawal of the movable contact from the fixed contact.