Electrical Works

'M&E' in construction refers to mechanical and electrical systems

Mechanical systems can include elements of infrastructure, plant and machinery, tool and components, heating and ventilation and so on. Electrical systems might include, power supply and distribution, telecommunications, computing instrumentation, control systems and so on.

In general, Electrical works  compose two main parts:  Electrical and ELV system ( Extra Low Voltage systems). These two main parts are the most important for all  civil and industrial building. These systems may take 40%-60% M&E works.

Electrical services are the systems installed in buildings to make them comfortable, functional, efficient and safe and might include: 

  • Energy distribution.
  • Energy supply (gas, electricity and renewable sources such as solar, wind, geothermal and biomass
  • Lighting (natural and artificial)
  • Lightning protection.

1. Power Supply System

     Main Power Supply is a part of Power Supply System. This function is useful for civil and industrial building. It compose these main factors: 

     Medium Voltage, Cast-Resin transformer 22kV/0.4kV and Moduled Case Circuit Breaker, MSB (Main Switch Board).

Submain Power Supply, AVR (Automatic Voltage Regulator system).Socket outlet system.

2. Backup Generator system

      Backup Generator System compose Generator, Auxiliary oil tank, Auxiliary oil pump (AOP), ATS, Synchro scope, UPS system. 

3. Lighting system

     Lighting or illumination is the deliberate use of light to achieve a practical or aesthetic effect. Lighting includes the use of both artificial light sources like lamps and light fixtures, as well as natural illumination by capturing daylight. Daylighting (using windows, skylights, or light shelves) is sometimes used as the main source of light during daytime in buildings. This can save energy in place of using artificial lighting, which represents a major component of energy consumption in buildings. Proper lighting can enhance task performance, improve the appearance of an area, or have positive psychological effects on occupants.

Indoor lighting is usually accomplished using light fixtures, and is a key part of interior design. Lighting can also be an intrinsic component of landscape projects.

4. Lightning Protection system

      Lightning protection systems are used to prevent or lessen lightning strike damage to structures. Lightning protection systems mitigate the fire hazard which lightning strikes pose to structures. A lightning protection system provides a low-impedance path for the lightning current to lessen the heating effect of current flowing through flammable structural materials. If lightning travels through porous and water-saturated materials, these materials may literally explode if their water content is flashed to steam by heat produced from the high current. This is why trees are often shattered by lightning strikes.

      The parts of a lightning protection system are air terminals (lightning rods or strike termination devices), bonding conductors, ground terminals (ground or "earthing" rods, plates, or mesh), and all of the connectors and supports to complete the system. The air terminals are typically arranged at or along the upper points of a roof structure, and are electrically bonded together by bonding conductors (called "down conductors" or "downleads"), which are connected by the most direct route to one or more grounding or earthing terminals. Connections to the earth electrodes must not only have low resistance, but must have low self-inductance..

       The majority of lightning protection systems in use today are of the traditional Franklin design. The fundamental principle used in Franklin-type lightning protections systems is to provide a sufficiently low impedance path for the lightning to travel through to reach ground without damaging the building. This is accomplished by surrounding the building in a kind of Faraday cage. A system of lightning protection conductors and lightning rods are installed on the roof of the building to intercept any lightning before it strikes the building.

5. Solar system

       Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into an electric current using the photovoltaic effect.