ARMY - AR TM 5-688
FOREIGN VOLTAGES AND FREQUENCIES GUIDE
|Publication Date:||12 November 1999|
This manual identifies the classes of electrical equipment that are sensitive to frequency and voltage variations. Appendix B covers identification of various low and medium voltage levels, along with the system frequencies, used by countries around the world. Derating factors are discussed and developed for the six generic types of equipment in chapter 3. Appendix C summarizes the derating factors presented in chapter 3 for different voltage and frequency environments.
This manual provides guidance required to identify the voltage and frequency standards of various foreign countries for both medium and low voltage systems. It also identifies the classes of equipment that are sensitive to voltage and frequency differences. Foreign countries around the world use different electrical standards for voltage and frequency than those of the United States. Some electrical equipment will operate properly at an electrical frequency of either 50 or 60 Hz. Equipment designed for 60 Hz that will not operate properly at 50 Hz is termed "50 Hz sensitive," and equipment designed for 50 Hz that will not operate properly at 60 Hz is termed "60 Hz sensitive."