Motor nameplate letter code designations
Motors built to National Electrical Manufacturers Association (NEMA) standards use alphabetical letter codes on the nameplate to designate a number of alternating current (AC) motor characteristics. These characteristics are the code, design, and insulation class. Read the nameplate carefully as these designations are easily misinterpreted. Similarly, re-confirm these data items when your customer provides them. For example, the letter "B" could designate a design code, insulation class or kVA code (though highly improbable.) What do these different designations mean?