Does the National Electrical Code ( NEC) permit the use of autotransformers?
Autotransformers are very common and recognized by all the safety and standard authorities. You can refer to N.E.C. Article 450-4, Autotransformers 600 Volts, Nominal, or Less, as a reference publication. Item (a) details overcurrent protection for an autotransformer and item (b) covers an isolation transformer being field connected as an autotransformer for a buck-boost application. 24. When a Buck-Boost transformer is connected as an autotransformer, what is the procedure for determining the current rating of the overcurrent protective device, such as the fuse or circuit breaker? The NEC Article 450-4 outlines overcurrent protection for autotransformers. It is reproduced as follows: NEC 450-4 – Autotransformers 600 Volts, Nominal, or Less (a) Overcurrent Protection. Each autotransformer 600 volts, nominal, or less shall be protected by an individual overcurrent device installed in series with each ungrounded input conductor. Such overcurrent device shall be rated or set at not more t
Autotransformers are very common and recognized by all the safety and standard authorities. You can refer to N.E.C. Article 450-4, “Autotransformers 600 Volts, Nominal, or Less”, as a reference publication. Item (a) details over-current protection for an autotransformer, and Item (b) covers an isolation transformer being field connected as an autotransformer for a Buck-Boost application.
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- Does the National Electrical Code ( NEC) permit the use of autotransformers?
