Question 1

Why does a small transformer cost so much more per kVA?

Accepted Answer

Because a large part of the cost is fixed regardless of rating. The tank, the cabinet, the bushings, the switches, the paint, the testing and the freight are broadly similar on a 75 kVA unit and a 500 kVA unit. Only the core and the windings scale with rating, so the fixed portion is spread over far fewer kVA at the small end.

Question 2

What makes a transformer quote go up?

Accepted Answer

Copper windings instead of aluminium, ester fluid instead of mineral oil, loop feed instead of radial, stainless or mill-grade enclosures, non standard voltages, 55 degree rise instead of 65, and expedited production. Each is a real cost, and each should appear as its own line rather than being bundled.

Question 3

Is freight included in a transformer price?

Accepted Answer

Usually not. Ask whether the price is ex works, FOB a port, or delivered to site, and get freight as a separate line. On a unit of several thousand pounds needing a flatbed and often a crane, freight is not a rounding error.

Scales with rating	Broadly fixed regardless of rating
Core steel	Tank and cabinet
Winding conductor	Bushings, elbows and switches
Insulating fluid volume	Paint, labour, testing, paperwork
	Freight and handling

Option	Effect	Worth it when
Copper instead of aluminium windings	Significant increase	The specification demands it, or space is tight
FR3 ester instead of mineral oil	Moderate increase	Fire clearance or environmental rules require it
Loop feed instead of radial	Moderate increase	Almost always, utilities require it
55 C rise instead of 65 C	Increase	Future load growth is expected
Stainless or mill grade enclosure	Increase	Coastal or corrosive environments
Expedited production	Large increase	The date is worth more than the money

What pad mounted transformers cost

The one thing to understand about transformer pricing

Options that move the number

Price by rating