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Where can I go to find out what a particular Square D voltage/tap code stands for? Example: 150T1840H, what does the ``1840`` stand for?

Contact Product Marketing/Support for assistance with identifying unknown parameters of Square D low voltage dry type distribution transformer catalog numbers.  Often, Product Marketing/Support (PM) can add value by evaluating the requested information with the application, and may be able to add valuable suggestions.

Example:  The ``1840`` stands for a primary of 480 delta to a secondary of 600 delta with no taps.  PM may offer that this type of voltage change is often used when feeding a 575 volt motor (575 volt motors are used on 600 volt systems.)  With most motors, electrical isolation is not required, but low regulation during startup is.  For this, PM may offer two standard single phase transformers in an open-delta autotransformer connection.  This has the benefit in this instance of being able to use (2) 25S3H transformers off the shelf -- no lead time, lower cost, and lower regulation during startup.  This transformer connection is shown on the bottom of page 11 of the Dry Type Transformer Application Guide, document # 7400HO9501 which is available via the link below.


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