P
[email protected]
- Jan 1, 1970
- 0
Would there be any real _technical_ limitations (as opposed to just fear
because such a thing is not common) for the design of a three phase dry
type transformer around a standard "E" core used in typical three phase
designs, with each of the 3 secondary windings wound for 240 volts with
a center tap on ALL THREE so each winding is really 120/240 volts? Are
there any issues with using such a transformer to supply strictly single
phase loads, assuming reasonable balance?
One issue I do see is that such a transformer would require more secondary
terminal connections. There would be 7 such connections if the neutral
were wired in common internally. Assume any requirement for "number of
disconnects" would be met by a single three phase primary disconnect.
I've never seen such a transformer in any of the marketing data I've seen
from many transformer manufacturers. But I don't see any real reason why
such a thing could not be designed and built, if there was a market for
it.
I do know this could very simply be done with three single phase 120/240
volt transformers. But what about using TWO separate "E" core dry-type
transformers where either the primary or secondary windings are reversed
in one of them such that one of them is 180 degrees rotated from the other.
Could this split combination be used to supply 120/240 volt single phase
loads where one 120 volt leg comes from one transformer, and the other 120
volt leg comes from the other that is 180 degrees offset? What if one of
the transformers loses power such as its primary breaker tripping? What
about triplen harmonics issues from 2-wire 240 volt loads?
because such a thing is not common) for the design of a three phase dry
type transformer around a standard "E" core used in typical three phase
designs, with each of the 3 secondary windings wound for 240 volts with
a center tap on ALL THREE so each winding is really 120/240 volts? Are
there any issues with using such a transformer to supply strictly single
phase loads, assuming reasonable balance?
One issue I do see is that such a transformer would require more secondary
terminal connections. There would be 7 such connections if the neutral
were wired in common internally. Assume any requirement for "number of
disconnects" would be met by a single three phase primary disconnect.
I've never seen such a transformer in any of the marketing data I've seen
from many transformer manufacturers. But I don't see any real reason why
such a thing could not be designed and built, if there was a market for
it.
I do know this could very simply be done with three single phase 120/240
volt transformers. But what about using TWO separate "E" core dry-type
transformers where either the primary or secondary windings are reversed
in one of them such that one of them is 180 degrees rotated from the other.
Could this split combination be used to supply 120/240 volt single phase
loads where one 120 volt leg comes from one transformer, and the other 120
volt leg comes from the other that is 180 degrees offset? What if one of
the transformers loses power such as its primary breaker tripping? What
about triplen harmonics issues from 2-wire 240 volt loads?