Distribution transformer calculations – MS Excel Spreadsheet

04/12/2025

Four Fast Transformer Calculations

The distribution transformer calculations spreadsheet enables rapid computations for the following: ascertaining the MV/LV transformer rating, calculating the rating of the overcurrent protection device on the low - voltage side of the transformer, determining the prospective short - circuit current, and computing the sizes of natural ventilation openings required for the transformer room.
Determining the MV/LV Transformer Rating
Input Parameters:
  • Primary Rated Voltage (kV)
  • Secondary Rated Voltage (kV)
  • Maximum Demand Load (kW)
  • Corrected Power Factor
  • Transformer Type
  • Permissible Loading Percentage (%)
  • Nearest Standard Transformer Rating (kVA)

Calculating the Rating of Overcurrent Protection Device on the Low - Voltage Side of the Transformer

Calculating the prospective short - circuit current on the low - voltage side of the transformer

Calculating the sizes of natural ventilation openings required for the transformer room.

 

 

 

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