低压变压器.第3部分:2级和3级变压器5085-31范围1。1如UL 5085-1或CSA C22《低压变压器第1部分:一般要求》所述。2 No.66.1，低压变压器-第1部分:一般要求，第3部分中的要求包括根据国家电气规范ANSI/NFPA 70或加拿大电气规范第一部分CSA C22与2级电路一起使用的2级变压器。1.它们用于连接基本上正弦的电源。建议注释:对于拟在美国使用的变压器，这些要求还包括根据国家电气规范ANSI/NFPA 70与3级电路一起使用的3级变压器，除非本标准中另有规定。3级要求见附录d。1.3除第1部分第1.3条规定的项目外，第3部分的要求不包括: a） 电源（配备整流器的变压器被视为电源）；b） 玩具变形金刚；c） 电线和插头连接的变压器；d） 直接插入式变压器；e） 用于音频、广播或电视类设备的变压器；orf）其他电气设备或器具要求中涵盖的其他特殊类型的变压器。建议注释:第3部分的要求不包括在美国使用的标称一次额定电压超过600 V的变压器和额定过电压超过660 V的变压器。1.7本部分拟与第1部分一起使用。第3部分中的条款编号与第1部分中的条款编号相对应。除非第3.1.8部分进行了修改，否则第1部分中的要求适用。第2类变压器包括一个单独的限流阻抗，如电阻器或正温度系数装置（PTC），属于这些要求的范围。 1.9包括谐振调节电路的2级变压器包含在这些要求中。

Low Voltage Transformers - Part 3: Class 2 and Class 3 Transformers5085-31 Scope1.1 As noted in Low Voltage Transformers - Part 1: General Requirements, UL 5085-1, or CSA C22.2 No. 66.1, Low Voltage Transformers - Part 1: General Requirements, the requirements in Part 3 cover Class 2 transformers for use with Class 2 circuits in accordance with the National Electrical Code, ANSI/NFPA 70, or the Canadian Electrical Code, Part I, CSA C22.1. They are intended for connection to essentially sinusoidal supply sources.Advisory Note: For transformers intended for use in the United States, these requirements also cover Class 3 transformers for use with Class 3 circuits in accordance with the National Electrical Code, ANSI/NFPA 70, unless otherwise specified in this standard. See Annex d for Class 3 requirements.1.3 In addition to the items specified in Clause 1.3 of Part 1, the requirements of Part 3 do not cover:a) Power supplies (a transformer provided with a rectifier is considered a power supply);b) Toy transformers;c) Cord and plug connected transformers;d) Direct plug-in transformers;e) Transformers intended for use in audio, radio, or television type appliances; orf) Other special types of transformers covered in requirements for other electrical devices or appliances.Advisory Note: The requirements of Part 3 do not cover transformers intended for use in the United States having a nominal primary rating of more than 600 V and transformers having overvoltage taps rated over 660 V.1.7 This part is intended to be used in conjunction with Part 1. The numbering of the clauses in Part 3 corresponds to the numbered clauses in Part 1. The requirements in Part 1 apply unless modified by Part 3.1.8 A Class 2 transformer that includes a separate current-limiting impedance such as a resistor or a positive temperature coefficient device (PTC) is covered by these requirements.1.9 A Class 2 transformer that includes a resonance regulating circuit is covered by these requirements.