In the implementation of electrical installations, the power grid, which is responsible for supplying electricity to home and industrial users, provides electricity depending on the amount of load requested by the user at different voltage levels, while household units provide power at 220 volts. They receive single-phase volts or finally 380 volts three-phase, industrial units receive power at levels of 20, 63 and even 132 kV due to their high energy demand, because the large size of an industrial unit transmits power from the point of delivery to the location. Accumulation of load at low voltage levels makes it impossible, because high current levels at low voltage will impose extremely high voltage drop s and losses on that industrial unit. In addition, many loads in an industrial unit, including some three-phase electric motors, operate at voltages above 400 volts, which requires access to high voltage levels. These two factors work together to receive power at voltage levels. The above and the subsequent justification of the initial costs in the construction of the internal conversion substation in order to reduce the level of voltage received in proportion to the loads installed in the factory.
Basic information:
At the beginning of the design of electrical installations, companies designing and implementing electrical installations need to gather information about the project to clarify the scope of work. For this purpose, the answers to the following questions must be specified
What are the environmental conditions such as maximum and minimum ambient temperature, altitude, humidity and air pressure?
Is the purpose of a new electricity project or the development and optimization of exist ing electrical installations?
What are the consequences of a power outage?
Is the power supply through the grid or is it supplied exclusively from within the unit (or both)?
Are there any specific points that need to be considered regarding the operation and maintenance of electrical installations?
Is it possible for volatile gases and vapors to escape inside the unit?
Has the electricity distribution company required the industrial unit to modify the power factor?
Is there a need for direct current power supply via battery or uninterruptible power supply (UPS) or uninterruptible power supply with diesel generator to increase reliability?
Initial step (load analysis):
In the first step, by taking the following steps and preparing a one-line map and load list, the necessary design basis with the details of the power plant will be provided.
In consultation with other specialties involved in the project (electrical, mechanical, building, etc. engineers), the main and ancillary equipment should be located.
Based on the location and determination of the location of accumulation of electrical charges, a preliminary single-line circuit should be prepared.
By receiving the necessary information from the departments of mechanics, chemistry and instrumentation, the total electrical power consumption of the exec utive installation project and the load of each of the considered panels should be estimated by considering the synchronization and dimensional coefficients.
(It is clear that some loads such as lighting, heat, sockets, etc. must be determined by the electrical department, but most of the loads, such as heating and cooling systems, pumps, compressors, blowers, motor valves, etc. must be estimated by the mechanical installation department and be provided to the electrical designer)