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Thread: Service Entrance @ Patio Cover
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02-16-2012, 08:49 AM #1
Service Entrance @ Patio Cover
The reason for this post is to understand (just maybe) how others are looking at the main SE to an inspected property. Lately, I have come across several properties that have Patio covers in which the vertical clearance of the "Service" coming into the Mast from the transformer is below industry standards. Simply put, does the standard specify "dwelling" roof tops or "all" roof tops? The attached photos are an example of my curiosity. Any input is always appreciated.
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02-16-2012, 08:58 AM #2
Re: Service Entrance @ Patio Cover
SECTION E3504
OVERHEAD SERVICE-DROP AND SERVICE
CONDUCTOR INSTALLATION
E3504.1 Clearances on buildings. Open conductors and
multiconductor cables without an overall outer jacket shall
have a clearance of not less than 3 feet (914 mm) from the sides
of doors, porches, decks, stairs, ladders, fire escapes and balconies,
and from the sides and bottom of windows that open. See
Figure E3504.1.
E3504.2 Vertical clearances. Service-drop conductors shall
not have ready access and shall comply with Sections
E3504.2.1 and E3504.2.2.
E3504.2.1 Above roofs. Conductors shall have a vertical
clearance of not less than 8 feet (2438 mm) above the roof
surface. The vertical clearance above the roof level shall be
maintained for a distance of not less than 3 feet (914 mm) in
all directions from the edge of the roof.
' correct a wise man and you gain a friend... correct a fool and he'll bloody your nose'.
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02-16-2012, 01:01 PM #3
Re: Service Entrance @ Patio Cover
Article 230.24 has many exceptions based on the voltage and other factors that do not require the 8' clearance listed above.
230.24 Clearances. Overhead service conductors shall not
be readily accessible and shall comply with 230.24(A)
through (E) for services not over 600 volts, nominal.
(A) Above Roofs. Conductors shall have a vertical clearance
of not less than 2.5 m (8 ft) above the roof surface.
The vertical clearance above the roof level shall be maintained
for a distance of not less than 900 mm (3 ft) in all
directions from the edge of the roof.
Exception No. 1: The area above a roof surface subject to
pedestrian or vehicular traffıc shall have a vertical clearance
from the roof surface in accordance with the clearance
requirements of 230.24(B).
Exception No. 2: Where the voltage between conductors
does not exceed 300 and the roof has a slope of 100 mm in
300 mm (4 in. in 12 in.) or greater, a reduction in clearance
to 900 mm (3 ft) shall be permitted.
Exception No. 3: Where the voltage between conductors
does not exceed 300, a reduction in clearance above only
the overhanging portion of the roof to not less than 450 mm
(18 in.) shall be permitted if (1) not more than 1.8 m (6 ft)
of overhead service conductors, 1.2 m (4 ft) horizontally,
pass above the roof overhang, and (2) they are terminated
at a through-the-roof raceway or approved support
All answers based on unamended National Electrical codes.
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02-16-2012, 01:57 PM #4
Re: Service Entrance @ Patio Cover
Referred to as "building".
California's version of the Electrical Code (Title 24, Part 3) can be viewed as hosted on the NFPA site in view only mode without having to sign-in or register by using the following clickable link here (javascript must be enabled and new windows to open, i.e. no pop-up blockers):
RealRead Viewer : California*Electrical*Code*2010
Hosted at NFPA in a read only version may be viewed without any sign-up/sign-in by using the link above.
2010 California Electrical Code,
California Code of Regulations
Title 24, Part 3
California Building Standards Commission
Based on 2008 National Electrical Code
Effective January 1, 2011.
IIRC the prior edition was similarly cited (Part 3, Title 24) as the 2007 version.
As you know (new) Part 2.5 of Title 24 (California Residential Code based on the IRC) does not incorporate Part VII, but instead refers one to Part 3 of Title 24, (may be viewed on-line here [clickable link]:
Part VIII - Electrical
Although IRC Chapter references from a non-california version of the IRC (and its neat illustration) doesn't necessarily apply, and is not enforcable, it might prove helpful to you to review the nearly identical language and its illustration (also a clickable link : Chapter 36 - Services
).
Using the link provided earlier above hosted at NFPA (California Electrical Code, Title 24, Part 3, repeated here for your convienence [clickable link]:
RealRead Viewer : California*Electrical*Code*2010
; when the viewer loads (a new window should open) with the California Electrical Code, use the table of contents icon (lower right) which will pop up yet another window, and click on the direct link to Section 230 (under Chapter 2) titled "Services"; you can then navigate page by page using the page arrow icons at the bottom of the viewer to the sections cited and quoted below.
Title 24, Part 3,
2010 California Electrical Code
Chapter 2,
Section 230 "Services", Sub-Part I:
230.9 Clearances on Buildings. Service conductors and final spans shall comply with 230.9(A), (B), and (C).(A) Clearances. Service conductors installed as open conductors or muliconductor cable without an overall outer jacket shall have a clearance of not less than 900 mm (3 ft) from windows that are designed to be opene, doors, porches, balconies, ladders, stairs, fire escapes, or similar locations.Exception: Conductors run above the top level of a window shall be permitted to be less than the 900-mm (3-ft) requirement.
(B) Vertical Clearance. The vertical clearance of final spans above, or within 900 mm (3 ft) measured horizontally of, platforms, projections, or surfaces from which they might be reached shall be maintained in accordance with 230.24(B)
(C) Building Openings. Overhead service conductors shall not be installed beneath openings through which materials may be move, such as openings in farm and commercial buildings, and shall not be installed where they obstruct entrance to these building openings.
Section 230, Sub-Part II Overhead Service-Drop Conductors.
230.24 Clearances. Service-drop conductors shall not be readily accessible and shall comply with 230.24(A) through (D) for services not over 600 volts, nominal.(A) Above Roofs. Conductors shall have a vertical clearance of not less than 2.5 m (8 ft) above the roof surface. The vertical clearance above the roof level shall be maintained for a distance of not less than 900 mm (3 ft) in all directions from the edge of the roof.Exception No. 1: The area above a roof surface subject to pedestrian or vehicular traffic shall have a vertical clearance from the roof surface in accordance with the clearance requirements of 230.24(B).
230.26 Point of Attachment. The point of attachment of the service-drop conductors to a building or other structure shall provide the minimum clearances as specified in 230.9 and 230.24. In no case shall this point of attachment be less than 3.0 m (10 ft) above finished grade.Exception No. 2: Where the voltage between conductors does not exceed 300 and the roof has a slope of 100 mm in 300 mm (4 in. in 12 in.) or greater, a reduction in clearance to 900 mm (3 ft) shall be permitted.
Exception No. 3: Where the voltage between conductors does not exceed 300, a reduction in clearance above only the overhanging portion of the roof to not less than 450 mm (18 in.) shall be permitted if (1) not more than 1.8 m (6 ft) of service-drop conductors, 1.2 m (4 ft) horizontally, pass above the roof overhang, and (2) they are terminated at a through-the-roof raceway or approved support.(B) Vertical Clearance for Service-Drop Conductors. Service-drop conductors, where not in excess of 600 volts, nominal, shall have the following minimum clearance from final grade:FPN: See 230..28 for mast supports.
Exception No. 4: The requirement for maintaining the vertical clearance 900 mm (3 ft) from the edge of the roof shall not apply to the final conductor span where the service drop is attached to the side of a building.
(1) 3.0 m (10 ft) -- at the electrical service entrance to buildings, also at the lowest point of the drip loop of the building electrical entrance, and above areas or sidewalks accessible only to pedestrians, measured from final grade or other accessible surface only for the service-drop cables upported on and cabled together with a grounded bare messenger where the voltage does not exceed 150 volts to ground.
(2) 3.7 m (12 ft) -- over residential property and driveways, and those commercial areas not subject to truck traffic where the voltage oes not exceed 300 volts to ground.(3) 4.5 m (15 ft) -- for those areas listed in the 3.7 m (12-ft) classification where the voltage exceeds 300 vlts to ground.(4) 5.5 m (18 ft) -- over public streets, alleys, roads, parking areas subject to truck traffic, driveways on other than residential property, and other land such as cultivated, grazing, forest, and orchard.(C) Clearance from Building Openings. See 230.9.
(D) Clearance from Swimming Pools. See 680.8.
230.28 Service Masts as Supports. Where a service mast is used for the support of service-drop conductors, it shall be of adequate strength or be supported by braces or guys to withstand safely the strain imposed by the service drop. Where raceway-type service masts are used, all raceway fittings shall be identified for use with service masts. Only power service-drop conductors shall be permitted to be attached to a service mast.
Not applicable or enforcable in California, but attached illustration from unammended 2009 IRC, might be found useful in applying the above.
Hope that helps.
P.S. Please get yourself an all wooden or fiberglass yardstick for use in such photo opporunities, not a flexible conductive spring tape. That grounded conductor *might* carry current. Unprotected exposure 7.5 kva plus! incidental contact potential - think about your safety as you were looking at your view finder/display not your hand or tape directly where a slight wind, change of angle, etc. might have bowed that spring tape, or an arc, static, etc. remember your PPE.
Last edited by H.G. Watson, Sr.; 02-16-2012 at 02:11 PM.
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02-16-2012, 03:29 PM #5
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