MO.tool
STANDARDS & FORMULAS

Single Line

The single line diagram drawn from the model: every board, what feeds it, its ways, cables and loads.

Standards and regulations

  • IEC 60617
    Graphical symbols for diagrams

    The symbols of the single line diagram.

  • BS 5467
    Armoured cables with thermosetting (XLPE) insulation, 600/1000 V

    The cable figures (mV/A/m) come from Ducab’s catalogue of XLPE cables made to it.

Formulas

Demand load

P(demand) = Σ P(connected) × demand factor

Cable drop shown on the diagram

Vd = (mV/A/m) × I × L / (runs × 1000), added up from the origin

  • The cable and its length come from the Voltage Drop tool

Design rules it applies

  • Checked first: what is missing on each board is listed before drawing
  • Breakers written with rating, poles and type (MCB / MCCB / ACB)
  • The supply written as typed (for example: FROM DEWA 11 kV NETWORK)
  • Update draws again from the model and keeps what you changed by hand

For reference. MO.tool works these out to help your design; the engineer remains responsible for it. Always check the edition of each standard your project uses and the requirements of the local authority (DEWA, ADDC, Civil Defence…).

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