(and when wired in reverse, step-down transformers) are used to make
large changes in voltage. Common configurations are 240V to
480V, 208V to 480V to name only a few. They are usually
available in both single-phase and three-phase models.
Transformers need to
be sized to the load they will supply and usually rated in KVA,
which is an acronym for “thousand volt
single-phase loads, multiply the operating voltage of the load by
the amps then divide by 1,000 to get the KVA. e.g. 240V x 30A
/ 1,000 = 7.2 KVA.
loads, multiply the operating voltage of the load by the amps,
multiply by 1.73 (square root of three) then divide by 1,000 to get
the KVA. e.g. 240V x 30A x 1.73 / 1,000 = 12.46 KVA.
Transformers and Phase Converters
transformers are commonly used in conjunction with phase converters.
A common application is the operation of 480V equipment. The
240V single-phase voltage must be stepped up to 480V, either through
a single-phase transformer before the converter, or a three-phase
transformer after the converter.
Be sure to consult a
knowledgeable supplier of
when choosing one for your application.