Service line over detached building

[Bob Ozbirn]

This detached building was added under an existing service drop. I assume a clearance of 3' would be required. Is this correct?

[James Duffin]

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 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 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.

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

[Roger Frazee]

This detached building was added under an existing service drop. I assume a clearance of 3' would be required. Is this correct?

Bob

Does it meet exception 2. Also the clearance above that detached building may change to more than minimums depending on the point of attachment to the service entrance of the building being served...ie...you have clearances that must be met between the detached building and the point of attachment. And you might even have to move the point of attachment vertically to maintain the necessary clearance over the detached building. Or you may have to involve the utility...

[Bob Ozbirn]

I believe it would meet exception 2 thus the 3' however it is only 12" to 18" above the roof. What confused me was "the roof surface" since this was not the roof in question. Seems to me it should say any roof surface.

[Roger Frazee]

I believe it would meet exception 2 thus the 3' however it is only 12" to 18" above the roof. What confused me was "the roof surface" since this was not the roof in question. Seems to me it should say any roof surface.

Believe me I understand your confusion.....:D


What you have isn't going to be acceptable. Some of the inspectors here can advise you how to call that out in your report ... I am assuming your doing an inspection. Give them some time they will be around to respond. I'm not a home inspector just a retired wireman.

[Jerry Peck]

I believe it would meet exception 2 thus the 3' however it is only 12" to 18" above the roof. What confused me was "the roof surface" since this was not the roof in question. Seems to me it should say any roof surface.


It should say "the roof surface" just as it does because it is referring to "the roof surface" you are measuring to.

Not 'the roof surface' where the conductors originate, but *the roof surface* the conductors are over.