Issue:
How is the secondary of a Single Phase Transformer with a 240/120V secondary wired to produce a neutral connection?
Product Line:
Low Voltage Transformers, LV Transformers
Environment:
Applies to Single Phase Transformers with dual 120V secondaries that can be wired for 240V, 120V, or both 240/120V.
Cause:
Users and Installers of transformers are accustomed to seeing an X0 neutral terminal on Three Phase Transformers.
Why is there no X0 on Single Phase Transformers?
Resolution:
X0 terminals are a feature of three phase transformers that have 208Y/120V Wye secondaries. Single Phase transformers never have three phase Wye secondaries, so the X0 designation does not apply.
For a Single Phase Transformer with dual 120V secondaries, to derive a 240/120V system with a neutral, connect terminals X2+X3, which will then be the neutral terminal. 240V will be available between X1 and X4. 120V will be available from either X1 or X4 to the X2+X3 neutral terminal.
For a Single Phase Transformer with dual 120V secondaries, to derive a 120V only system, connect X2+X4 together as the neutral terminal. Connect X1+X3 together as the 120V line terminal.
How is the secondary of a Single Phase Transformer with a 240/120V secondary wired to produce a neutral connection?
Product Line:
Low Voltage Transformers, LV Transformers
Environment:
Applies to Single Phase Transformers with dual 120V secondaries that can be wired for 240V, 120V, or both 240/120V.
Cause:
Users and Installers of transformers are accustomed to seeing an X0 neutral terminal on Three Phase Transformers.
Why is there no X0 on Single Phase Transformers?
Resolution:
X0 terminals are a feature of three phase transformers that have 208Y/120V Wye secondaries. Single Phase transformers never have three phase Wye secondaries, so the X0 designation does not apply.
For a Single Phase Transformer with dual 120V secondaries, to derive a 240/120V system with a neutral, connect terminals X2+X3, which will then be the neutral terminal. 240V will be available between X1 and X4. 120V will be available from either X1 or X4 to the X2+X3 neutral terminal.
For a Single Phase Transformer with dual 120V secondaries, to derive a 120V only system, connect X2+X4 together as the neutral terminal. Connect X1+X3 together as the 120V line terminal.
Released for: Schneider Electric USA
