Autotransformers with neutral connections now available in stock

We’re pleased to announce that our new line of Autotransformers with neutral terminals is now available in stock. The new line uses the same part number structure but has a 3L0U suffix that indicates the neutral terminals are provided. The attached table shows the old vs. new part numbers and new UPC codes.

Autotransformers without neutrals continue to remain available and both options can be configured in our e-Quotes system.

The new Autotransformers provide our customers with a common (H0/ X0) neutral connection point that is connected by the factory to the middle point of the Y winding configuration.

When selecting this option special attention should be given to the neutral and grounding connections in compliance with the electrical codes in North America. HPS recommends that both the Line and Load side neutral cables must be connected to the respective neutral terminals in order to ensure the proper operation of the autotransformer. Furthermore the H0/X0 point should not be grounded locally to avoid a multiple ground situation.  Click here to learn more about connecting the neutral and grounding.

When installing the autotransformer please refer to the local electrical code requirements for grounding and short circuit protection of a three phase autotransformer and if necessary review your specific application with the local inspection agency.

Typical Wiring diagram:

Old to New Autotransformer Part Numbers and New UPC codes: