John - If you look at the Section after the sentence "The following constructions are considered to satisfy the requirement without test:" in paragraph 4.4.6. I believe the last item, the metal screen, would be the your simplest solution for the larger vent openings (of course you should use holes lager than .125" with this solution). Or, if you want to get creative, then check out Figure 12, Baffle plate construction. Otherwise, you must have the hot flaming oil test (A5) performed on any perforation not listed on the table. Regards, Mike Campi Corporate Compliance Engineer Fujitsu PC Corporation
-----Original Message----- From: John Juhasz [mailto:[email protected]] Sent: Monday, October 04, 1999 7:39 AM To: '[email protected]' Subject: Screen Dimensions - Fire Enclosures Hi group. With reference to UL 1950 3rd. Ed., Table 15 (size and spacing of holes in metal bottoms of fire enclosures) , I would like some opinions . . . the largest size listed in the table is 1.00mm minimum metal thickness, 2.00mm maxhole dia., and 3.00mm minimum center-center hole spacing. If my metal thickness was greater (1.27mm), and my center-center hole spacing was 4.75mm, could I not go to a larger hole (3.175 - .125")? The reason I pose this question is that the dmensions I was thinking about using are for a 'standard' punch that a sheet metal fabricator would have. UL told me that what's they won't consider it because it's not listed on the chart. I am trying to tell my mechanical designer to use standard perforated stock which falls within the UL guidelines (there is stuff readily available) but he needs more airflow (without fans) . . . Has anyone been there? John Juhasz Fiber Options Bohemia, NY --------- This message is coming from the emc-pstc discussion list. To cancel your subscription, send mail to [email protected] with the single line: "unsubscribe emc-pstc" (without the quotes). For help, send mail to [email protected], [email protected], [email protected], or [email protected] (the list administrators).
