Electrical design for factories is a critical factor determining operational efficiency. A properly designed electrical system, adhering to standards, not only ensures the safety of personnel and machinery but also optimizes energy consumption and minimizes the risk of production interruptions.
So, how do you design an effective electrical system for a factory? In this article, BIC will guide you through the detailed steps of designing a factory electrical system, from the initial survey to construction and acceptance. Let's explore!
When designing an electrical system for a factory, adhering to technical standards is crucial to ensure safety and operational efficiency. Below are some important standards to keep in mind:
- Electrical Safety Standards: The factory's electrical system must comply with regulations such as TCVN (Vietnamese Standards), IEC (International Electrotechnical Commission), and NEC (National Electrical Code) to ensure the system's safety and durability.
- Power and Usage Efficiency Requirements: The electrical design needs to accurately calculate the power consumption of all equipment to avoid overloading or wasting energy.
- Lightning Protection and Grounding System: The factory needs to be equipped with a compliant grounding system to minimize the risk of short circuits and protect machinery from electrical incidents.
- Fire Prevention and Fighting Standards: The electrical system must be designed to minimize the risk of fire and explosion, while complying with regulations regarding fire-resistant materials, safety distances, and electrical protection devices.
Adhering to the above standards not only helps the factory's electrical design system operate stably but also ensures the safety of workers and company assets.
Incorrect electrical design in a factory can lead to numerous safety and operational efficiency risks. Therefore, businesses need to adhere to specific design steps to ensure the electrical system operates stably, safely, and cost-effectively.
The calculated load is a crucial parameter for determining the total power consumption of electrical equipment at a specific time. This serves as the basis for selecting and verifying critical equipment in the electrical system, such as transformers, conductors, and switchgear. Additionally, the calculated load helps to estimate power losses, voltage, and to choose appropriate reactive power compensation capacity.
Determining the electrical load plays a pivotal role in the design of the electrical system because:
- If the calculated load is lower than the actual load: The system may be overloaded, leading to electrical failures or reduced equipment lifespan.
- If the calculated load is higher than the actual load: It leads to wasted energy, equipment operating below its full capacity, and costly investments.
Therefore, accurately calculating the load helps engineers determine the power requirements for each area within the factory. This allows them to select equipment, conductors, and materials that are suitable for the electrical system. Furthermore, the calculation should consider future expansion and development to ensure the system operates efficiently in the long term.
After determining the calculated load, the next step is to create a detailed drawing of the high-voltage power grid system to ensure a stable power supply for the entire factory.
A high-voltage power grid is an electrical system with a nominal voltage from 35kV to 220kV, playing the role of transmitting electricity from the national grid to the factory. Common voltage levels include:
- 110kV - 220kV - 500kV: Bare conductors, installed on spun concrete poles, steel lattice towers, or wooden poles with a height of 18m or more.
- 35kV and below: Can use post insulators or porcelain insulators according to technical standards.
- 500kV: 24 insulators/string
- 220kV: 12 – 14 insulators/string
- 110kV: 6 – 9 insulators/string
- 35kV: 3 – 4 insulators/string or use post insulators
- Below 35kV: Use post insulators
The high-voltage system is designed to transmit electricity from the national grid to the factory's substation. Therefore, the design drawing needs to clearly show:
- Location of power poles: Ensuring safe distances and compatibility with the factory layout.
- Selection of appropriate number of porcelain insulators: Based on the required voltage level of the business.
- High-voltage power lines entering the factory: Determining the optimal route to reduce power loss and installation costs.
- Substation layout: Located in a convenient position for power distribution and maintenance.
- Distribution cabinets: Arranged logically according to each production area to ensure efficiency and electrical safety.
Accurately designing the high-voltage power grid not only helps businesses have a stable power system but also ensures operational safety, optimizes costs, and creates conditions for future expansion.
A low-voltage electrical network is a system that directly supplies electricity to equipment and machinery within factories and workshops, with a nominal voltage ranging from 0 to 1kV (typically 220V - 380V). Designing this system requires ensuring safety, stability, and sufficient power capacity for production operations.
- Common Voltage Levels: 220V (single-phase) and 380V (three-phase).
- Conductors: Utilize twisted insulated cables (Aerial Bundled Cables/ABC) with an insulated sheath, ensuring safety and minimizing electrical leakage.
- Installation Method: Conductors are fixed on poles using suspension clamps or insulators.
- Poles: Made of spun concrete, square concrete, or steel towers, with heights ranging from 5m to 8m depending on design requirements.
- Location of Control Cabinets: Should be placed in central areas, convenient for operation and maintenance.
- Conductor System: Distribute reasonably according to each production area, ensuring no obstruction to the working process.
- Electrical Safety: Use circuit breakers (CBs), overload protection, and earth leakage protection to ensure system safety.
- Expansion Provision: Design the system with flexibility to allow for upgrades or expansions when needed.
Low-voltage electrical network design must ensure scientific principles, energy efficiency, and safety for workers. A reasonable layout will help optimize operations, minimize incidents, and extend the lifespan of the factory's electrical design.
The lighting system plays a vital role in the production activities of a factory. Insufficient lighting can cause difficulties for workers, affecting productivity and safety. Conversely, installing too many lights can lead to unnecessary energy consumption for the business. Therefore, the lighting system in a factory's electrical design must ensure appropriate brightness, reasonable distribution, and energy efficiency.
To design an accurate lighting system, the following parameters need to be calculated:
- Total required luminous flux:
- Total lamp power:
- Number of lamps required:
After determining the number of lamps, the design drawing should clearly show the installation positions to ensure:
- Suitable light intensity, avoiding glare or affecting the eyesight of workers.
- Even light distribution, preventing blind spots or shadows caused by obstructions.
- Reasonable spacing between lamps, creating the best lighting effect.
- Selection of light close to natural light, helping to reduce eye strain and create a comfortable working environment.
Scientific lighting system design helps optimize work performance, save electricity costs, and ensure workplace safety in the factory.
Power factor correction systems play a crucial role in stabilizing voltage, increasing electrical efficiency, and reducing reactive power losses. A well-designed power factor correction system will help factories optimize power usage, reduce operating costs, and extend the lifespan of equipment.
- Stabilizes voltage at load points, enabling equipment to operate efficiently.
- Reduces energy losses, optimizing the power transmission system.
- Increases the load-bearing capacity of power lines, making the electrical system more stable.
- Reduces electricity costs, especially costs due to low power factor.
- Extends the lifespan of electrical equipment by maintaining a stable power level.
When designing a power factor correction system, it is necessary to accurately calculate the reactive power to select the appropriate capacitor bank size. Common design approaches include:
- Centralized Capacitor Bank: Located at the main distribution panel, helping to correct the power factor for the entire system.
- Zone-based Capacitor Bank: Distributing capacitor banks to individual workshops to optimize efficiency.
- Individual Equipment Capacitor Bank: Typically applied to large motors, but costly in terms of installation and management.
- The location for installing capacitor banks should be based on the factory structure to ensure optimal effectiveness.
- Avoid installing capacitor banks too far from the power source to minimize voltage drop.
- Use automatic capacitor banks so that the system can adjust the compensation power according to actual needs.
Designing a properly standardized power factor correction system not only reduces power loss but also optimizes factory production operations, ensuring a stable power supply and long-term cost savings.
Electrical design for factories is a complex process, requiring precise calculations and strict adherence to technical standards. Following the correct design procedures not only ensures workplace safety but also helps businesses optimize operating costs, extend equipment lifespan, and minimize electrical risks. A high-quality electrical system will support efficient production, minimizing incidents and disruptions to business operations. Therefore, businesses should invest in a reputable design construction company to obtain a safe and sustainable electrical solution.
