git:20260704.5e814f8 to git:20260714.ed4504e

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name: taipower-indoor-wiring-ampacity

description: "This skill should be used when calculating or verifying the allowable ampacity (current-carrying capacity) of indoor electrical wiring and conduit fill limits according to the Taipower Indoor Wiring Regulations (屋內線路裝置規則)."

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# Taipower Indoor Wiring Ampacity & Conduit Fill

## Context & Purpose

This skill encodes the regulations for indoor electrical wiring (屋內線路裝置規則) specifically focusing on the allowable ampacity of wires inside conduits (PVC or Metal) and ambient temperature corrections.

## Parameters & Tables (Based on Article 16)

### 1. Baseline Conditions

- **Standard Ambient Temperature**: 35°C

- **Standard Conductor Insulation Temp**: 60°C (e.g., PVC), 75°C (e.g., XLPE/PE), or 90°C.

- **Wire Material**: Copper (銅)

### 2. Ampacity for PVC Wire in Conduit (60°C Insulation, 35°C Ambient) - Partial Table (Table 16-7)

| Wire Size (mm²) | Ampacity for ≤ 3 wires | Ampacity for 4 wires | Ampacity for 5-6 wires |

|-----------------|------------------------|----------------------|------------------------|

| 2.0 mm (Solid) | 19 A | 16 A | 14 A |

| 3.5 mm² | 19 A | 16 A | 14 A |

| 5.5 mm² | 25 A | 23 A | 20 A |

| 8 mm² | 33 A | 30 A | 25 A |

| 14 mm² | 50 A | 40 A | 35 A |

| 22 mm² | 60 A | 55 A | 50 A |

| 38 mm² | 85 A | 75 A | 65 A |

| 50 mm² | 100 A | 90 A | 80 A |

| 100 mm² | 160 A | 150 A | 125 A |

*(Note: Neutral wire, grounding wire, and control wires are generally not counted in the "number of wires" for ampacity derating, unless harmonics are present).*

### 3. Voltage Drop (Article 9)

- **Feeder + Branch Circuit**: Total voltage drop must not exceed **5%** of the nominal voltage.

- **Feeder only or Branch only**: Voltage drop must not exceed **3%**.

## Execution Logic for AI

When reviewing a single-line diagram (單線圖) or wiring schedule:

1. Identify the wire size (e.g., 8 mm²) and the number of current-carrying conductors in the conduit.

2. Cross-reference with the ampacity table to find the maximum allowed current.

3. Compare the allowed current with the specified breaker size (AT/AF). The wire's ampacity must be ≧ the breaker's trip setting (AT), with exceptions for motor loads.

4. Verify voltage drop calculations do not exceed 3% for branches or 5% total.