Service Drop Clearance Over Roof

[Mark R. Long]

Am I correct that this service drop is too close to the house roof? (I realize that the pictures aren't showing this very well).

The service drop comes in over an addition and at the closest point, clears the roof by about 10". It continues over the addition, approximately 12' in length, until it gets to the mast. At that point it is clearing the roof by about 24".

[Paul W. Abernathy]

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 traff

ýc 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
(4 in.) in 300 mm (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.

[Mark R. Long]

Thanks Paul! So if I understand you correctly, what you are saying is that I should quit being such a lazy dumb--s and read the damn book myself!

[Paul W. Abernathy]

Nope...I am saying......since it is easier to understand the NEC than my garbled messages...I would just post the code and the answer is within.

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. 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.

[Paul W. Abernathy]

If the clearance is over the house portion and the pitch is less than 4/12...AND if we are not talking about an overhang....meaning the service drop you are speaking of runs right across an open roof.....it is wrong.

If we are talking about it just going over a small corner of it and the roof has a pitch that is as steep as a 4/12 or more.....It can be reduced.....likely no one would get near it to be involved with it.

Ok....How close is your MAST from he edge of the house Mark?

Would THIS apply to your example...I really can't tell from the images

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.

[Pierre Belarge]

Service drop conductors over roof, roof overhangs and separate structures on the same property seem to be "missed" during inspection processes. This is not just an NEC code, but also an NESC (utility) code as well. I have taken many photos of just what you have and many others as well.

[Mark R. Long]

Originally Posted by pabernathy

If the clearance is over the house portion and the pitch is less than 4/12...AND if we are not talking about an overhang....meaning the service drop you are speaking of runs right across an open roof.....it is wrong.

If we are talking about it just going over a small corner of it and the roof has a pitch that is as steep as a 4/12 or more.....It can be reduced.....likely no one would get near it to be involved with it.

Ok....How close is your MAST from he edge of the house Mark?

Would THIS apply to your example...I really can't tell from the images

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.

The mast, itself, is on the side of the house, but the service drop does not go to the mast from that side of the house. It goes over an open roof on a newer addition for about 12', in order to get to the mast. The mast location had been changed at some point in time, it appears about two years ago. It used to be on a different side of the house. I'm guessing that it was relocated to accommodate the new addition and/or because a deck was built under the service drop and the clearance to the deck would not have been adequate after the deck was built.

I'm also hypothesizing that perhaps the utility installed the service drop before the new addition was actually built and the contractor/homeowner built the addition under the service drop. It still should have been picked up though on a final inspection for the addition, if there was a final.

Anyway, I've noted it as wrong and in need of further evaluation and correction. Thanks Paul!