Hello, I've been following with great interest the discussion between Mike Rains and Rich Nute about the fire enclosure issue. I would like to add my two cents worth now.
First if the supply is UL Recognized one should check the Conditions of Acceptability to determine what must be considered in the end-product. It may very well state the need for a fire enclosure. If you are the manufacturer of a power supply to be submitted for UL (or other NRTL) Recognition, then read on. Second, subclause 4.4.5.1 identifies components requiring a fire enclosure while subclause 4.4.5.2 specifically identifies situations where a fire enclosure would not be required. Subclause 4.4.5.1 specifically requires a fire enclosure for components having windings such as transformers. Even components within a limited power source may have to be located within a fire enclosure. Neither of these subclauses would seem to exclude primary circuits tested according to clause 5.4 from having a fire enclosure. Regards, Scott
