Comments on: In Compliance, by Chip Carson PE http://inspector911.com/in-compliance-by-chip-carson-pe/228 Resources, Checklists, and Training for inspectors with NFPA and the ICC codes Fri, 10 Sep 2010 12:59:57 +0000 http://wordpress.org/?v=2.9.2 hourly 1 By: Greg Masters http://inspector911.com/in-compliance-by-chip-carson-pe/228/comment-page-1#comment-143 Greg Masters Tue, 09 Dec 2008 01:07:22 +0000 http://inspector911.com/?p=228#comment-143 Regarding the requirement for dry type transformers over 112.5 kVA to be installed in a 1-hour rated room: The article is correct, but leaves out the fact that there are two exceptions to the section (Section 450.21 of the NEC) that contains this requirement. The exceptions are: 1. Transformers with Class 155 or higher insulation systems and separated from combustible material by a fire-resistant, heat-insulating barrier or by not less than 6 feet horizontally and 12 feet vertically. 2. Transformers with Class 155 or higher insulation systems and completely enclosed except for ventilating openings. I have actually worked with the local electrical inspectors to enforce this requirement in new construction for several years. In many cases, the designers don't balk, and agree to the 1-hour electrical room with no questions asked. In other cases, they have demonstrated that the installation would meet Exception 2, and we didn't get the rated room. Regarding the requirement for dry type transformers over 112.5 kVA to be installed in a 1-hour rated room:

The article is correct, but leaves out the fact that there are two exceptions to the section (Section 450.21 of the NEC) that contains this requirement. The exceptions are:
1. Transformers with Class 155 or higher insulation systems and separated from combustible material by a fire-resistant, heat-insulating barrier or by not less than 6 feet horizontally and 12 feet vertically.
2. Transformers with Class 155 or higher insulation systems and completely enclosed except for ventilating openings.

I have actually worked with the local electrical inspectors to enforce this requirement in new construction for several years. In many cases, the designers don’t balk, and agree to the 1-hour electrical room with no questions asked. In other cases, they have demonstrated that the installation would meet Exception 2, and we didn’t get the rated room.

]]> By: Craig Rauch http://inspector911.com/in-compliance-by-chip-carson-pe/228/comment-page-1#comment-138 Craig Rauch Fri, 05 Dec 2008 20:46:55 +0000 http://inspector911.com/?p=228#comment-138 I am not sure I follow all of Mr. Winkler’s comments. I fully agree that the governing building code must be taken into consideration. It was, however, my impression that a building would be considered fully suppressed by the IBC even if you omit sprinklers in accordance with the provisions of NFPA 13. In addition would you not consider a building fully suppressed if Item 1,2,3 or 4 of IBC 903.3.1.1.1 were used? I am not sure I follow all of Mr. Winkler’s comments. I fully agree that the governing building code must be taken into consideration.

It was, however, my impression that a building would be considered fully suppressed by the IBC even if you omit sprinklers in accordance with the provisions of NFPA 13. In addition would you not consider a building fully suppressed if Item 1,2,3 or 4 of IBC 903.3.1.1.1 were used?

]]> By: Mike Winkler http://inspector911.com/in-compliance-by-chip-carson-pe/228/comment-page-1#comment-137 Mike Winkler Fri, 05 Dec 2008 13:56:46 +0000 http://inspector911.com/?p=228#comment-137 The answer is incomplete and accordingly inaccurate because it does not take into account other codes that may apply. The Building Code allows a designer to take advantage of code trade offs by agreeing to install fire sprinklers throughout the building. When this trade off is used, such as in unlimited area buildings, water sprinklers are still required in electrical rooms. IBC/MBC section 903.3.1.1.1 clearly states that water sprinklers shall not be omitted from any room merely because it has electrical equipment. The ICC has published formal interpretations that state the electrical room must also have fire sprinklers. The answer is incomplete and accordingly inaccurate because it does not take into account other codes that may apply. The Building Code allows a designer to take advantage of code trade offs by agreeing to install fire sprinklers throughout the building. When this trade off is used, such as in unlimited area buildings, water sprinklers are still required in electrical rooms.

IBC/MBC section 903.3.1.1.1 clearly states that water sprinklers shall not be omitted from any room merely because it has electrical equipment. The ICC has published formal interpretations that state the electrical room must also have fire sprinklers.

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