谐波滤波器计算器

使用此谐波滤波器计算器快速获得准确的计算结果。

Conductor Cross Section

mm²

Allowable Current Density

A/mm²

3-5 for enclosed, 5-8 for open air

Derating Factor

For temperature, grouping, etc.

System Voltage

Derated Ampacity

24.0 A

Base Ampacity30.0 A

Max Power at This Ampacity5,520 W

Max Power5.52 kW

Derated Ampacity vs Conductor Cross Section

查看公式 →

公式

Cable Ampacity Estimation

Ampacity is the maximum continuous current a conductor can carry without exceeding its temperature rating.

Formula

Ampacity = Cross Section x Current Density x Derating Factor

Current Density Guidelines

Open air: 5-8 A/mm^2

In conduit: 3-5 A/mm^2

Underground: 2-4 A/mm^2

Derating Factors

Ambient temperature above 30 C: 0.7-0.9

Multiple cables in conduit: 0.5-0.8

Direct burial: 0.7-0.85

Always verify with NEC/IEC tables for your specific installation.

计算示例

6 mm^2 copper cable, 5 A/mm^2, derating 0.8, at 230 V.

01Base ampacity: 6 x 5 = 30 A
02Derated: 30 x 0.8 = 24 A
03Max power: 24 x 230 = 5,520 W = 5.52 kW

常见问题

Is this a substitute for NEC/IEC tables?

No. This provides estimates. Always use the applicable electrical code tables for final cable sizing in real installations.

What happens if I exceed ampacity?

The cable overheats, insulation degrades, and eventually a fire hazard develops. Overcurrent protection (breakers/fuses) should prevent this.

How does cable length affect sizing?

Longer cables have more resistance, causing voltage drop. You may need to upsize the cable beyond ampacity requirements to limit voltage drop.

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