標準號：UL 5085-3-2006
中文標準名稱：低壓變壓器.第3部分:2類和3類變壓器
英文標準名稱：Low voltage transformers - Part 3: Class 2 and Class 3 transformers
標準類型：K41
發(fā)布日期：2006/4/17 12:00:00
實施日期：1999/12/31 12:00:00
中國標準分類號：K41
國際標準分類號：29.180
適用范圍：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. 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; or f) 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. 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. 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. A Class 2 transformer that includes a resonance regulating circuit is covered by these requirements.