Distribution transformer calculations – MS Excel Spreadsheet

Four Fast Transformer Calculations

Distribution transformer calculations spreadsheet provides fast calculations for the following: Determining the MV/LV transformer rating, calculating overcurrent protection device rating on the low voltage side of the transformer, calculating the prospective short circuit current and Calculating natural ventilation openings sizes required for the transformer room.

1. Determining the MV/LV transformer rating

Input parameters:

• Primary rated voltage (kV.)
• Secondary rated voltage (kV.)
• Max. demand load (kW)
• Power factor after correction
• Transformer type
• Permissible loading percentage (%)
• The nearest standard transformer rating (KVA)

2. Calculating overcurrent protection device rating on the low voltage side of the transformer

3. Calculating the prospective short circuit current across the low voltage side of the transformer

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