How far is the transformer substation from the distribution box

The distance between a transformer substation and a distribution box typically ranges from a few meters within a building to several hundred meters in a low-voltage network, depending on system design and load density.

Typical Spacing

In urban or densely-loaded areas, medium-voltage (MV) or low-voltage (LV) distribution substations are often spaced 500–600 meters apart, with the output from the transformer connected to distribution boxes or link boxes along the network . In less dense areas, distances can be longer, and the network may use radial or branched configurations to supply multiple distribution points efficiently . Within a building or facility, the distribution box is usually located as close as possible to the transformer to minimize voltage drop and improve operational efficiency. Indoor substations often place the low-voltage distribution room adjacent to the transformer room, sometimes on the same floor or directly above/below with proper isolators if on different floors . For safety, oil-filled transformers are generally kept outside or in a separate room from the main distribution panels to reduce fire risk .

Factors Affecting Distance

1. Voltage Level: Higher voltage systems can tolerate longer distances due to lower current and reduced voltage drop, while low-voltage circuits require closer placement.
2. Load Density: Areas with high electrical demand require more closely spaced distribution boxes to maintain voltage quality and reliability.
3. Safety and Maintenance: Adequate spacing is needed for safe operation, maintenance access, and fire prevention, especially for oil-filled transformers .
4. Network Configuration: Radial, looped, or branched networks influence the placement of distribution boxes relative to the substation .

Practical Guidelines

• Indoor substations: Place the LV distribution room as close as possible to the transformer room, ideally on the same floor or with a short vertical connection using isolators if on different floors .
• Outdoor networks: Distribution boxes (link boxes or pillars) are positioned along the feeder lines, typically hundreds of meters from the substation, depending on urban density and load requirements .
• Fire and safety considerations: Maintain separation between oil-filled transformers and distribution rooms, and provide containment for potential oil spills . In summary, the exact distance varies based on system voltage, load, and safety requirements, but in practice, distribution boxes are placed as close as feasible to the transformer in buildings, while in street-level networks, distances of 500–600 meters between substations and distribution points are common.