1、UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULUL TECHNICAL GUIDANCE DOCUMENTSThis Document is prepared and published by UL.Product Category (CCN): IFDHStandard Number: UL 1838Standard Title: Standard for Low Voltage Landscape Lighting System
2、sEdition Date: January 13, 2003Edition Number: 3Section / Paragraph Reference: 1.10, Section 22.3Subject: Secondary isolation for LED driversGUIDANCE:LED drivers that comply with UL 8750 must additionally be evaluated for compliance with the output circuitisolation requirements of UL 1838 section 22
3、3.RATIONALE FOR GUIDANCE:Clause 1.10 requires LED components, including drivers, to comply with UL 8750. However, UL 8750does not require the same level of primary-to-secondary isolation as UL 1838 section 22.3. This does notreflect any conflict in requirements between UL 8750 and UL 1838 but inste
4、ad that UL 1838 products areinstalled in a more restrictive environment than anticipated by many UL 8750 applications. Specifically, thewet location environment and allowance for full user accessibility to the UL 1838 luminaires supplied bythe power unit drive the need for greater power unit safegua
5、rds against the risk of electric shock. Therequired safeguards are provided by the transformer isolation or double insulation requirements of UL1838 section 22.3.Copyright 2018 UL LLCULs Technical Guidance Documents are intended to be used as reference documentation and aredesigned to provide assist
6、ance in understanding the application of requirements contained in thecorresponding UL Standard, provide assistance in addressing the use and applications of the respectiveproducts covered by the associated UL Standard(s), or both.These guidelines do not contain any construction or performance requirements.UL COPYRIGHTED MATERIAL NOT AUTHORIZED FOR FURTHER REPRODUCTION ORDISTRIBUTION WITHOUT PERMISSION FROM ULSTANDARD NUMBER: UL 1838 -2-No Text on This Page
