AIEE Standard for Aircraft Direct- Current Apparatus Voltage Ratings

It has been widely recognized that there is a distinct need for preferred voltage ratings for aircraft direct-current electric apparatus which will be generally acceptable to manufacturers and users to serve as a basis for voltage standards for aircraft systems and equipment. Many difficulties and much confusion will be eliminated by adopting suitable standard voltage ratings for all aircraft electric equipment. These standard voltages should then be made a part of specifications and nameplates marked accordingly. Apparatus should be designed for satisfactory operation over the voltage ranges given in the table, but with performance not necessarily the same as guaranteed at rated voltage. Performance data and acceptance tests should be on the basis of standard voltages. It is recognized that special applications may require operation over other voltage ranges than those shown as standard.