Factory power loads fluctuate greatly, with numerous motors and equipment, strong harmonic interference, and significant start-stop impacts. Transformer selection differs from that in residential areas. The core selection points are as follows:
1. Accurate Load Calculation: Calculate capacity based on the total power of the plant's equipment and the simultaneity factor. For motors such as machine tools, fans, and pumps, the starting inrush current must be considered, reserving approximately 30% for future expansion. Full-load configuration is strictly prohibited.
2. Equipment Type Selection: For outdoor plants and open spaces, low-loss oil-immersed transformers are preferred due to their good heat dissipation, strong overload capacity, and low cost. For workshops, enclosed plants, and flammable/explosive workshops, dry-type transformers should be used to ensure fire safety.
3. Harmonic and Short-Circuit Resistance Requirements: Factories have numerous frequency converters and rectifiers, resulting in high harmonic content. Transformers with harmonic resistance and high-strength winding technology should be prioritized to avoid overheating, excessive losses, and equipment aging caused by harmonics. Improve short-circuit impedance standards to cope with frequent motor starting impacts.
4. Energy efficiency adaptation: Production factories operate 24 hours a day without stopping, and the no-load loss has a great impact. It is necessary to select the new national standard low-loss model to significantly reduce the long-term production electricity cost.
