Design Guide for Rural Substations
Design Guide for Rural Substations (photo credit:

Purpose and scope

This bulletin covers rural transmission and distribution with air-insulated, outdoor substations 345 kV (phase-to-phase) and below. Possible design responsibilities of the engineer are covered, including preparation of construction drawings, material, equipment and labor specifications, and any other engineering design services that may be required.

Relationship of substation to overall power system

A substation is part of a system and not an entity to itself. Normally, a power system is designed so that the effects of an outage (caused by the failure of a single component such as a transformer, transmission line, or distribution line) will result in minimal interruption of service and affect the fewest customers possible.

Failure of one component in a system often forces a greater than normal load to be carried by other components of the system. Such contingencies are normally planned for and incorporated into design criteria.

Basic Switching Substation
Basic Switching Substation

Importance of adequate substation planning and engineering

Substation planning considers the location, size, voltage, sources, loads, and ultimate function of a substation.

If adequate planning is not followed, a substation may require unnecessary and costly modification.

The engineer’s detailed work requires use of valid requirements and criteria, appropriate guidelines, and engineer’s own expertise in order to provide construction drawings and associated documents appropriate for needed system improvements.

The engineer’s ability to meld the diverse constraints into an acceptable design is essential.

Title:Design Guide for Rural Substations – United States Department of Agriculture – Rural Utilities Service
Size:10 MB
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Design Guide for Rural Substations
Design Guide for Rural Substations

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  1. […] substations come in many sizes and configurations. A small rural substation may have a nominal rating of 5 MVA while an urban station may be over 200 […]

  2. Manas Kundu
    Mar 29, 2015

    Want to know if in USA they specify Copper winding for rural substation specifically or any metal does?
    Thanks for clarifying.

  3. V.Natarajan
    Mar 25, 2015

    DESIGN GUIDE TO RURAL SUBSTATION FIle IS Damaged.Will you please upload it again

    • Edvard
      Mar 25, 2015

      I just checked again, download and I can read it, without any errors. Maybe your download was interrupted somehow…

    • Edvard
      Mar 25, 2015

      I just saw that something strange is happening when I try to download in Internet Explorer. Try using Chrome or Firefox.

  4. pankaj
    Aug 22, 2014

    wht is this quest

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