23 January 2021
The Isolation provided by Isolation Transformers can be electrically beneficial
Applies to all Transformers by SquareD/Schneider Electric, except Autotransformers
Isolation is automatically provided by Transformers with a separate primary and secondary
The word `Isolation` denotes an electrically separate primary and secondary, a definition that applies to all Transformers except Autotransformers. Isolation Transformers can be used for the special purpose of reducing certain types of electrical disturbances from transferring from the primary service to secondary loads, particularly if the Transformer secondary is a separately derived system that can be bonded to a new, `clean` earth reference or ``ground``. When the secondary of the Isolation Transformer will not be grounded, the addition of an electrostatic shield between the primary and secondary of the Isolation Transformer can provide a limited amount of additional protection against certain kinds of electrical disturbances. If the secondary of the transformer is referenced to ground, an electrostatic shield is not necessary. When ordering Transformers, the term `Isolation` does not imply electrostatic shield. The electrostatic shield must be specified.
For more information on SquareD/Schneider Electric Shielded Isolation Transformers see Square D Publication 7400PD9202 attached to this page.