There are 2 main reasons for the need to transform from three phases to two phases,
- To give a supply to an existing two phase system from a three phase supply.
- To supply two phase furnace transformers from a three phase source.
TEC incorporates a special three phase core design which has two windings, the main and
teaser, the centre limb is 41% larger in section and left unwound.
The three phase side is connected in a Tee formation, with the main winding wound for
the full line volts and centre tapped, this winding is also interleaved so that any
magnetic effect of a current entering at the centre point is cancelled out. The teaser
winding is wound for 87% of the line volts with one end connected to the centre point of
the main winding.
Each secondary is a simple single phase winding with the volts and amps no different
from what would be expected in an ordinary single phase transformer.
Qs = KVA rating of 2 phase load.
