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T/F: rural design, transformer size first

Short answer

False. Rural loads are clustered at settlements; the load centre location is fixed first. Transformer size is then selected to match that cluster's demand, followed by LT conductor and feeder length.

State whether the following statement is TRUE or FALSE. Justify your answer with a brief explanation: For design of rural distribution first select the transformer size and then size of the load centre.

FALSE.

Justification

In rural areas the loads are not uniform; they appear as clusters (villages, settlements, market centres) separated by empty land. The design must therefore start from the load centre, not from the transformer size.

Correct sequence for rural distribution design:

  1. Survey the area and identify the settlements (load clusters) and the number and type of consumers.
  2. Estimate the present and forecast demand of each cluster (e.g. 0.3–0.5 kW per household with diversity, plus small industries, irrigation pumps).
  3. Locate the load centre (centre of gravity of the loads) of each cluster:
x=∑Pixi∑Pi,y=∑Piyi∑Pix = \frac{\sum P_ix_i}{\sum P_i},\quad y = \frac{\sum P_iy_i}{\sum P_i}
  1. Then select the transformer size (standard 25, 50, 100 kVA) to match the forecast demand of that load centre, keeping reserve for growth.
  2. Choose LT conductor and length so that voltage drop and loss at the farthest consumer stay within limits; extend the 11 kV line to the transformer.
PointReason
Load fixed by village locationEngineer cannot move the load
Transformer serves one clusterIts size depends on that cluster's demand
Low load densityLT lines long; drop decides spacing

So the load centre is chosen first and the transformer is sized to it. Selecting a transformer size first and then "sizing the load centre" reverses cause and effect.

✓ Answer checked by Claude Opus 5.5 (high effort)

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