1. Core Calculation Methodology of Wiring Specifications

The fundamental electrical relationship is expressed as$$I = \frac{P}{V}$$
Where:

• $I$ = Current (Amperes)
• $P$ = Rated power (e.g., 37 kW or 37,000W)
• $V$ = Operating voltage (typically 380V for industrial equipment)

For a 37 kW machine$$I = \frac{37,000}{380} \approx 97.37\,\text{A}$$

2. Wire Sizing Based on Current and Conditions

Referencing international standards, copper wire ampacity follows these guidelines:

• Standard Conditions (25°C indoor):
  • Minimum: 25 mm² (safe carrying capacity: ~100A)
  • Recommended: 35 mm² for margin (58A/mm² × 35mm² = 203A)
• Adjusted for Environmental Factors:
  • High-temperature areas (＞40°C): Increase size by 10-15%
  • Long cable runs (＞50m): Upsize to compensate for voltage drop

3. Key Selection Criteria

4. Practical Implementation Steps

1. Calculate Current: Use the formula above.
2. Select Wire:
   • For 97.37A: 35 mm² copper cable (stranded for flexibility)
   • Add 20% safety margin → 120A → 50 mm²
3. Verify Voltage Drop: Ensure ＜3% for 380V systems.

5. Pro Tips for Optimization

• Use oil-resistant flexible cables (e.g., H07RN-F) for mobile installations.
• Separate power and control wiring to prevent interference.
• Install circuit breakers rated at 125% of operating current (e.g., 125A for 97A load).

Final Recommendation:
Always consult a certified electrician to validate calculations against local regulations. For dynamic industrial environments, periodic cable inspections are critical to maintain safety and efficiency.

: 导线截面积与载流量的计算(Calculation of cross sectional area and Ampacity of conductors) – 豆丁网