Distribution transformer

A distribution transformer or service <a href="/facts/Transformer/EYYfXWrF">transformer</a> provides a final <a href="/facts/Voltage/EN2po6N2">voltage</a> transformation in the <a href="/facts/Electric_power_distribution/F5NfTeWP">electric power distribution</a> system, stepping down the voltage used in the distribution lines to the level used by the customer.
The invention of a practical, efficient transformer made <a href="/facts/AC_power/EXsaw0B9">AC power</a> distribution feasible; a system using distribution transformers was demonstrated as early as 1882.
If mounted on a <a href="/facts/Utility_pole/wRPdk0VI">utility pole</a>, they are called pole-mount transformers. When placed either at ground level or underground, distribution transformers are mounted on concrete pads and locked in steel cases, thus known as distribution tap <a href="/facts/Padmount_transformer/pGbyDJPs">pad-mount transformers</a>.
Distribution transformers typically have ratings less than 200 <a href="/facts/Volt-ampere/6R2WrK7b">kVA</a>, although some national standards allow units up to 5000 kVA to be described as distribution transformers. Since distribution transformers are energized 24 hours a day (even when they don't carry any load), reducing <a href="/facts/Magnetic_core/yojywmuo">iron losses</a> is vital in their design. They usually don't operate at full load, so they are designed to have maximum efficiency at lower loads. To have better efficiency, <a href="/facts/Voltage_regulation/lPfFAfcp">voltage regulation</a> in these transformers should be kept to a minimum. Hence, they are designed to have small <a href="/facts/Leakage_reactance/NhAPzcne">leakage reactance</a>.

Distribution transformer open-in-new

Distribution transformer