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What is Square D`s standard tap offering on low voltage dry type distribution transformers with primary voltages at or below 277 volts?

Square D offers as a standard for primary voltages from 190 through 277 volts two 5% full capacity below nominal (2 - 5% FCBN) taps. Square D also offers the transformer without taps, or with two 5% taps, one full capacity above nominal and one full capacity below nominal (2-5% 1+1-).

Square D offers the 2-5% FCBN tap at this voltage range as it makes the most sense, both commercially and from an application standpoint.
Taps are not usually changed on a transformer for small variations in voltage. When your input voltage is 277 volts or below, it is not likely that a tap would need to be changed until the difference approaches 5%. Also, having both taps below is the most useful as if the voltage varies from nominal in most systems in this range, it tends to be on the low side.

Note: Square D does not offer taps on transformers below 10kVA, except as noted in the Digest.


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