UL 1585:2001 pdf download Class 2 and Class 3 Transformers
1 Scope
1.1 Transformers covered by these requirements, herein called Class 2 or Class 3 transformers, are foruse with Class 2 or Class 3 circuits, respectively, in accordance with the National Electrical CodeANSINFPA 70. They are intended for connection to essentially sinusoidal supply sources. Permanentlyconnected transtormers are rated 600 volts or ess. and cord and plug connected transtormers are rateo120 volts or less.
1.2 A Class 2 or Class 3 transformer that is inherently limited has an impedance within the transformerthat limits the current output to a particular maximum value. t may or may not be provided with athermostat or other temperature sensitive device to limit its maximum temperature.
1.3 A Class 2 or Class 3 transformer that is not inherently limited does not have an impedance to limitthe maximum current output to a specified value. However, the maximum power output is limited by anovercurrent-protective device.
1.4 A Class 2 or Class 3 transformer that includes a separate current-limiting impedance, such as aresistor or a positive temperature coefficient device (PTC), is covered by these requirements.
1.5A Class 2 transformer has a 30-volt rms maximum secondary potential under any condition of loadingor open circuit.
1.6 A Class 2 or Class 3 transformer that includes a resonance regulating circuit is covered by theserequirements.
1.7 These requirements do not cover power supplies, toy transformers, direct plug-in transformers, ortransformers intended for use in audio-, radio-, or television-type appliances. A transformer provided witha rectifier is considered to be a power supply.
1.8 The requirements in this standard may be modified by requirements in an end product standard if atransformer is intended for use only as a component in other equipment.
1.9 A product that contains features, characteristics, components, materials, or systems new or diferentfrom those covered by the requirements in this standard, and that involves a risk of fire or of electric shockor injury to persons shall be evaluated using appropriate additional component and end-productrequirements to maintain the level of safety as originally anticipated by the intent of this standard. Aoroduct whose features,characteristics, components, materials, or systems conflict with specificrequirements or provisions of this standard does not comply with this standard. Revision of requirementsshall be proposed and adopted in conformance with the methods employed for development, revision, andimplementation of this standard.
1.9 revised February 28,2001
2 General
2.1 Components
2.1.1 Except as indicated in 2.1.2, a component of a product covered by this standard shall comply withthe requirements for that component. See Appendix A for a list of standards covering components usedin the products covered by this standard.
2.1.1 revised February 28, 2001
2.1.2 A component is not required to comply with a specific requirement that:
a) lnvolves a feature or characteristic not required in the application of the component in theproduct covered by this standard,or
b) ls superseded by a requirement in this standard.2.1.2 revised February 28, 20012.1.3 A component shall be used in accordance with its rating established for the intended conditions ofuse.
2.1.3 revised February 28.2001
2.1.4 Specific components are incomplete in construction features or restricted in performancecapabilities. Such components are intended for use only under limited conditions, such as certaintemperatures not exceeding specified limits, and shall be used only under those specific conditions.
2.1.4 revised February 28,2001
2.2 Units of measurement
2.2.1 Values stated without parentheses are the reauirement, Values in parentheses are explanatory orapproximate information.
2.2.1 revised February 28.2001