Loading...
HomeMy WebLinkAboutIR 8547 INFORMAL REPORT TO CITY COUNCIL MEMBERS NO. 8547 Date: December 2, pRi f�} tL4")11 To the Mayor and Members of the City Council 2003 Page 1 of 3 SUBJECT: Alternate Method for Wiring Application for 500 Throckmorton (The Tower) On November 13, 2003 the Construction and Fire Prevention Board of Appeals (CFPBOA) considered an application for an alternate method of wiring for the Tower project located at 500 Throckmorton. The Tower project is the reuse of the storm damaged Bank One building and proposes to renovate the building into commercial and residential uses. The Board was asked to consider an alternative electrical wiring method for the entire remodel project. After receiving testimony from both the building owner representative and interested parties, the Board denied the request. The applicant has 10 days to appeal this decision to district court. While the Board did deny the request, this alternate method will most likely be further discussed in the future as the City considers revisions and/or updates to the adopted Electrical Code. To insure the Council has a general understanding of this issue, the following outlines the existing code, the proposed alternate method end the pros and cons expressed at the November 13`h hearing. Existing Electric Code On June 5, 2001, the City Council approved Ordinance No. 14650 which established the 1999 National Electrical Code (NEC) and Local Amendments as the adopted electrical code for Fort Worth. A portion of the electrical code sets the minimum standard for wiring in both residential and commercial installations. This code establishes the limits in which non metallic (NM) cable can be used in construction. NM is the electrical wiring you might see in the attic or walls of residential or commercial (lower floors) construction. It may be white or smoky white in color with a white, black and bare copper wire inside. It is sometimes called Romex; however, Romex is a brand name for one particular manufacturer's brand of NM cable. Other companies may or may not have a brand name. The product is approved for commercial or residential installation. It is approved for wood or metal stud installation. In the 1999 National Electrical Code (NEC), NM cable is limited to use in buildings not exceeding three stories in height. Fort Worth's local amendment permits it in four story, wood or metal stud, residential uses. To the reverse, Fort Worth's amendment removes the code-authorized installation in commercial metal stud application. The three-story limitation was installed in the NEC in 1975. The justification for the three-story limitation is unknown and has been recently challenged. Fort Worth's adopted electrical code requires electrical wiring above the forth floor to be either metal clad (MC) or armor cable (AC). These two types are electrical wires side either conduit or a pre-manufactured metal casing. ISSUED BY THE CITY MANAGER FORT WORTH, TEXAS INFORMAL REPORT TO CITY COUNCIL MEMBERS NO. 8547 Date: December 2, ,ueo���O +�, 2003 r To the Mayor and Members of the City Council �. Page 2 of 3 n 1K ` SUBJECT: Alternate Method for Wiring Application for 500 Throckmorton �rsr� (The Tower) The 2002 NEC was amended to permit NM cable in buildings up to 6 stories high. While the 2002 NEC, not yet adopted in Fort Worth, allows its use up to 6 stories, the International Electrical Code, the companion code to the City's adopted international Building Code, permits use of NM cable in unlimited story installation. Note that the International Electrical Code is an administrative document that adopts the 2002 NEC with some amendments. One such amendment is to remove the story limitation for NM cable. The Tower's Proposed Alternate Method The Tower applied to the CFPBOA for permission to use the International Electrical Code as an alternate to the currently adopted 1999 National Electrical Code. While the Building Official does have the administrative authority to approve an alternate such as this, subject to challenge to the Board, it is common practice to take new code amendments and adoptions to the Board. The applicant proposed to install MC or AC wiring to each floor of the building and terminates this method at the individual panel boxes of each tenant or residential space. From the panel box the owner would use NM cable to each fixture within the unit. This method would exceed the requirements of the International Electrical Code since the wiring to each panel box could be wired with NM. Under the existing adopted NEC or 2002 NEC, NM wiring would not be allowed above the third or sixth floor, respectfully. All wiring above the set height limits would have to be MC or AC. The applicant believed that the installation of wiring in accordance with the International Electrical Code would be as safe as the NEC requirements and would save the project an estimated $1 50,000. The staff report (attached) raised no opposition to a favorable consideration of this request. The electrical industry was opposed to the alternate method. Those in attendance from the industry included electricians, electrical contractors, wiring manufactures, the International Brotherhood of Electrical Workers, North Texas Chapter of the National Electrical Contractors Association and Fort Worth Firefighters Association Local 440. Representatives from the electrical industry stated their belief that NM wiring beyond the NEC limits is not safe. Future Actions The applicant had 10 days to appeal the decision to District Court. While no action is presently scheduled for Council consideration on this issue, this topic will be part of the deliberations to adopt future codes. Staff anticipates the code review and Council consideration would occur in mid-2004. ISSUED BY THE CITY MANAGER FORT WORTH, TEXAS INFORMAL REPORT TO CITY COUNCIL MEMBERS No. 8547 Date: December 2, r To the Mayor and Members of the City Council 2003 Page 3 of 3 SUBJECT: Alternate Method for Wiring Application for 500 Throckmorton (The Tower) Summary Staff believes the limited usage on NM wiring inside dwelling units, on any story, is a wiring method whose prohibition needs further review. The NM method of wiring from the panel boxes to each fixture takes into account the necessary loads and provides a safe method regardless of which floor of a structure it occurs upon. Additionally, this method of wiring would make numerous projects more affordable and supports the City's strategic goal of revitalization of the Central City. Should Council members have additional questions regarding this issue, you may contact Al Godwin, Building Official or Bob Riley, Development Director. a . Jac o City Manager Attachment ISSUED BY THE CITY MANAGER FORT WORTH, TEXAS Staff Report Item No. 12 AMN 500 Throckmorton. Date: November 3, 2003 Case No. 04-16 Applicant: Bruce Benner Sections: 336-5 Fort Worth Electrical Code Article 336-5 of the Fort Worth Building Code states: 336-5. Uses Not Permitted. (a) Types NM, NMC, and NMS. Types NM, NMC, and NMS cables shall not be used in the following: '(1) In any multifamily dwelling or other structure exceeding three floors above grade. (FW amendment) Exception: An additional level shall be permitted in multifamily dwellings where the entire structure is protected throughout by an approved automatic sprinkler system For the purpose of this article, the first floor of a building shall be that floor that has 50 percent or more of the exterior wall surface area level with or above finished grade. One additional level that is the first level and not designed for human habitation and used only for vehicle parking, storage, or similar use shall be a permitted. (2) As service-entrance cable . (3) In commercial garages having hazardous (classified) locations as provided in Section 511-3 (4) In theaters and similar locations, except as provided in Article 518, Places of Assembly (5) In motion picture studios (6) In storage battery rooms (7) In hoistways (8) Embedded in poured cement, concrete, or aggregate (9) In any hazardous (classified) location, except as permitted by Sections 5014(b), Exception, 5024(b), Exception, and 504-20 (10) In non-residential metal frame structures. (FW amendment) Staff Comments: The applicant is representing a project that is currently in the process of converting a high-rise office building into a mixed-use residential and commercial building. In a Change Of Use conversion, it is normally required to bring the building up to current code. However, the Board has already reviewed the packet of alternates and variances for this building. r This request is not a variance. As such, it does not affect the first packet already reviewed by the Board. This request is to use an alternate code for the electrical installation. The code requested is the 2003 International Code Council Electrical Code. Staff would point out that the International Electrical Code is a code of administrative, provisions that adopts the 2002 National Electrical Code with some modifications. Of particular concern is Section 1202.2 which provides for the use of NM (Romex), NMC and NMS cable wiring without any limitation to height, number of stories or construction type of the building. In short, allowing the use of Romex cable pulled through grommets inserted in metal studs instead of pulled wiring in conduit pipes: The applicant states that approval of this request would save approximately$150,000. While the explanation of this code provision is quite detailed, staff will try to summarize the situation first, then provide documentation for the Board's reference. Preview There are some members on the Board that may remember the conflicting presentations that occurred when staff proposed the International Plumbing Code for adoptions. There were many statements from each side that created difficulty in the evaluation of the new code. Some such comments were that the IPC was not a safe code. One such item that was highlighted for its supposedly non-safety feature was the use of PVC Drain Waste and Vent piping in buildings over three stories in height. Even though Plumbing Codes east of the Mississippi river had allowed PVC DWV in high rise construction since its creation, for some unexplained reason, the other plumbing code limited PVC DWV piping to three stories, leaving only cast iron plumbing for construction over three stories. Cast iron plumbing cost more in material and labor. There were other downtown residential conversions under consideration at that time. Staff collected data from those designers. The numbers we received for the difference between PVC vs. cast iron ranged from $160,000 to $450,000 in cost savings. For reference, the architects state that the difference between cast iron vs. PVC on this job is $370,000. The item for review in this case is the limitation of NM (Romex) cable to three stories. As stated by the applicant, they predict a savings of$150,000. Current Regulation The 1999 National Electrical Code (NEC) sections that are pertinent are as follows: 3364.Uses Permitted. Type NM,Type NMC, and Type NMS cables shall be permitted to be used in the following: (1) One-and two-family dwellings (2) Multifamily dwellings and other structures,except as prohibited in Section 336-5 (3) Cable trays,where the cables are identified for the use. 336-5. Uses not Permitted. (a) Types NM,NMC, and NMS. Types NM,NMC, and NMS cables shall not be used in the following: (1) In any multifamily dwelling or other structure exceeding three floors above grade. (FW amendment) Exception: An additional level shall be permitted in multifamily dwellings where the entire structure is protected throughout by an approved automatic sprinkler system. (FWamendment) (10)In non-residential metal frame structures. Explanation: NM cable was limited to three-story construction by the NEC. No justification has been presented for this limitation. Fort Worth added an Exception for a fourth floor to permit NM cable in four story apartments. This could be wood or metal stud construction. NM cable was permitted to be used with metal studs by the NEC. A Fort Worth amendment Number (10), that became a COG amendment in 1998, prohibited its usage in metal studs except for residential uses. Evolution of Change This topic was reviewed under the International Electrical Code process. It*was pointed out that the three-story limitation was put in the 1974 changes to the NEC without any sustaining justification. The State of Michigan never adopted that limitation. They continued to permit NM cable in any building regardless of story or construction type. As such, there were two code changes proposed in the International Code process as follows: (From the State of Michigan) Exception: The use of Type NM,NMC and NMS cable wiring,methods shall not be limited based upon the height,number of stories or construction type of a bW14 ing or structure. (From the National Multi Housing Council, National Apartment Association, and the American Seniors Housing Association) Exception: The use of Type NM,NMC and NMS ng _MS cable wiring methods in a build or structure, or portions thereof, of Group R-2 shall not be limited based upon the height,number of stories or construction!3Me of the building or squcwg,. There were opponents to the code change. There comments were generally as follows: 1. NM cable is not safe over three stories. (Yet, no manufacturer has limited their product to three stories.) i Or 2. Manufacturers didn't feel it necessary to limit their product to three stories, relying on the NEC to do that. (However, this argument goes away later when the 2002 NEC removes the three-story limitation.) 3. Installation in metal studs is not safe. (Yet, the NEC has never-prohibited the installation in metal studs. It is recognized by NEC as an acceptable installation method.) 4. NM cable is unsafe for taller buildings. (Thus, NM cable is somehow safer in shorter non-sprinklered wood buildings than it would be in taller sprinklered non- combustible buildings.) Both code changes were approved. Since the Michigan code change was much broader than the Multi Housing code change, that is the change that was printed as a new Section 1202.2 as follows: 1202.2 Nonmetallic-sheathed cable. The use of Type NM,NMC and NMS (Nonmetallic sheathed) cable wiring methods shall not be limited based on height,number of stories or construction type of the building or structure. These same discussions were occurring at the NEC forum. The same arguments, same challenges, same reasons. One of the proposed changes was approved and the 2002 NEC was amended as follows: 334.10 Uses Permitted. Type NM,Type NMC,and Type NMS cables shall be permitted to be i used in the following: (1) One-and two-family dwellings. (2) Multifamily dwellings permitted to be of Types III,IV, and V construction except as prohibited in 334.12. (3) Other structures permitted to be of Types I11,N,and V construction except as prohibited in 334.12. Cables shall be concealed within walls, floors, or ceilings that provide a thermal barrier of material that has at least a 15-minute finish rating as identified in listings of fire- rated assemblies. (4) Cable trays,where the cables are identified for the use. (Note: The reference left out Type I and 11 construction which was permitted in the 1999 NEC It was not clear how to address those types. Therefore,an attemps to install an amendment under the"Not Permitted"provision was submitted the following year as follows) (1) In Type I or 11 construction unless permitted to be Types III,IV,or V construction. The three-story regulation in the NEC was replaced with Types III, IV and V construction which can be up to four, five or six stories. Since this change did not clearly address Types I and 11, those construction types were addressed with a followup amendment the next cycle. However, this has been further clarified in later code discussions. The NEC still permits NM cable to be used with metal studs. There was no explanation as to why the amendment stopped at four, five and six stories. There was no explanation as to how NM cable, which supposedly was dangerous over O'`� r� three stories, is now acceptable up to six stories. And, no manufacturer has put a limitation on the height of their product. Current situation The Electrical Subcommittee at COG has rejected the 2002 NEC amendments and proposes a code change to revert back to the 1999 NEC wording. Fort Worth did opposed this position but lost by one vote. The Fort Worth staff will be presenting this topic for discussion during the 2003 code adoption process. Attached are copies of the code changes to the International Electrical Code. It fully explains the position of the State of Michigan and the National Multi Housing Council. Staff Position The Chief Electrical Inspector points out that this request is in conflict with the city electrical ordinance#14650 section # 336-4 and 5 and the 1999 National Electrical Code section # 336-4 and 5. The current code sections, as amended, are as follows: 336-4.Uses Permitted. Type NM,Type NMC, and Type NMS cables shall be permitted to be used in the following: (4) One- and two-family dwellings (5) Multifamily dwellings and other structures,except as prohibited in Section 336-5 (6) Cable trays, where the cables are identified for the use. +� 336-5. Uses not Permitted. (a) Types NM,NMC, and NMS. Types NM,NMC, and NMS cables shall not be used in the following: (1) In any multifamily dwelling or other structure exceeding three floors above grade. (FW ame dmeno Exception: An additional level shall be permitted in multifamily dwellings where the entire structure is protected throughout by an=roved automatic sprinkler system. (FW amendment) (10)In non-residential metal frame structures. Additionally, while the 2002 NEC has been amended to reference Type III, N and V buildings, there continues to be proposed amendments on how to clarify this issue. Attached, is a copy of Report 7-115 from the National Electrical Code Technical Correlating Committee. The item of discussion is whether to keep separate sections "Uses Permitted" and "Uses not Permitted" or to combine them into one section. In the various comments it would appear that Type I and II buildings are actually covered by the current wording. The implication is that the new 2002 NEC wording should be interpreted as follows: 334.10 Uses Permitted. Type NM,Type NMC,and Type NMS cables shall be permitted to be used in the following: (1) One-and two-family dwellings. (2) Multifamily dwellings (of any construction type which could be)permitted to be of Types III, IV,and V construction except as prohibited in 334.12. (3) Other structures(of any construction type which could bq)Rennitted to be of Types III,LIV, and V construction except as prohibited in 334.12. Cables shall be concealed within walls, floors,or ceilings that provide a thermal barrier of material that has at least a 15-minute finish �� rating as identified in listings of fire-rated assemblies. (4) Cable trays, where the cables are identified for the use. It also deserves noting that when the 1975 National Electrical Code limited this product to three-story, it also established a 140° F allowable ampacities limitation to this product for safety. This action added.a safety factor to the use of Romex which compensated for usage in almost any application. In short, without justification the product was limited to three stories at the same time an extra safety factor was added to compensate for an expanded range of use. The 2002 NEC, without explanation, has expanded the usage in any construction type provided the building complies with the limitations of Type III, IV or V construction. There is no prohibition on usage with metal studs. And, there is no explanation as to why the product is limited to the limitation of these construction types. As such, the Chief Electrical Inspector has no opposition to favorable consideration of this request with the following stipulation: The use of NM cable must comply with all other applicable provisions in the 2002 NEC, and NM cable will be limited to the floor of origin, meaning that it will only be used for feeders and branch circuit power distribution on a single floor. Exception: The cable may be used throughout a multi-floor dwelling unit. The Building Official states that the three-story limitation was never justified during the code discussions. Even though many opponents clung to it as a necessary requirement, once the NEC removed the three story limitation, those arguments fell by the wayside. As with the three story limitation, no justification has been shown as to why the NEC stopped at the.limitations of a Type III, IV or V building (four, five and six stories). The Building Official has no opposition to favorable consideration to this request. If approved, this would be the first expanded usage of NM cable; therefore, the Building Official believes that the stipulation by the Chief Electrical Inspector would be appropriate. The Fire Marshal supports the Building Official. Board Decision: Date: