Nec service conductors clearance

[Tanelectrical]

In chapter 225.19 Clearances From Buildings for Conductors of Not Over 1000 Volts, Nominal of the NEC. It states

Overhead spans of open conductors and open multiconductor cables shall have a vertical clearance of not less than 2.7 m (8 ft 6 in.) above the roof surface. The vertical clearance above the roof level shall be maintained for a distance not less than 900 mm (3 ft) in all directions from the edge of the roof.

Further down it then allows a few exceptions to the 8ft rule one of the exceptions is as follows.

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.

My question is does the three feet in all directions of the roof apply to the exceptions? Or is it three feet when it passes over the roof up to the edges ?

 

[don_resqcapt19]

The rule is a vertical clearance rule and only applies above the roof. The rule starts as soon as the cable is above the roof.
Note that your post heading says service conductors and nothing in Article 225 applies to service conductors. The service conductor rule is in 230.24.

 

[Tanelectrical]

Thank you so much for the clarification I just seem like such a grey area to me I just wanted to verify if it was three feet off the edges then mast would have to be ridiculously high

 

[mtnelect]

Where is the "Demarcation Line" from the utility requirements to the NEC requirements. Is it at the meter ?

 

[don_resqcapt19]

Where is the "Demarcation Line" from the utility requirements to the NEC requirements. Is it at the meter ?

That is totally up to the utility. They define the service point and everything on the load side of the service point is governed by the NEC.
For all of the commercial installations in our area the utility has defined the service point as the secondary terminals on the transformer that supplies the service.
However, even where the conductors in question are utility owned, the National Electrical Safety Code, has the same clearance requirements. In general utilities are governed by the NESC.

 

[Tanelectrical]

That is totally up to the utility. They define the service point and everything on the load side of the service point is governed by the NEC.
For all of the commercial installations in our area the utility has defined the service point as the secondary terminals on the transformer that supplies the service.
However, even where the conductors in question are utility owned, the National Electrical Safety Code, has the same clearance requirements. In general utilities are governed by the NESC.

My utility company does not specify in there diagram clearance from the roof so I’m going with NEC which would be vertical clearance correct ?

 

[mtnelect]

That is totally up to the utility. They define the service point and everything on the load side of the service point is governed by the NEC.
For all of the commercial installations in our area the utility has defined the service point as the secondary terminals on the transformer that supplies the service.
However, even where the conductors in question are utility owned, the National Electrical Safety Code, has the same clearance requirements. In general utilities are governed by the NESC.

In California it is governed by The ESR Manual provides guidance and instructions pertaining to electrical service connections. Its purpose is to assist electrical contractors, engineers, architects, and manufacturers engaged in the installation of electrical service wiring and equipment.

 

[don_resqcapt19]

My utility company does not specify in there diagram clearance from the roof so I’m going with NEC which would be vertical clearance correct ?

Where is the service point?
In general, if you make your installation so that the service drop (utility conductors) or overhead service conductors (customer owned conductors) will be in compliance with the NEC, you will be fine.

 

[don_resqcapt19]

In California it is governed by The ESR Manual provides guidance and instructions pertaining to electrical service connections. Its purpose is to assist electrical contractors, engineers, architects, and manufacturers engaged in the installation of electrical service wiring and equipment.

no idea of what ESR is or who it is written by

 

[Tanelectrical]

Where is the service point?
In general, if you make your installation so that the service drop (utility conductors) or overhead service conductors (customer owned conductors) will be in compliance with the NEC, you will be fine.

My utility companies actually does specify what it says for clearance from the roof It just says service conductors must clear roof by 3 feet so that must just mean vertical. Not extending past the roof like nec says

 

[mtnelect]

no idea of what ESR is or who it is written by

Electrical Service Requirements - Each utility has their own ESR, so first check with each jurisdiction.

 

[mtnelect]

The NEC code has no jurisdiction over the utilities.

 

[don_resqcapt19]

Electrical Service Requirements - Each utility has their own ESR, so first check with each jurisdiction.

I though that is what I said:

That is totally up to the utility. They define the service point and everything on the load side of the service point is governed by the NEC....

 

[mtnelect]

That is totally up to the utility. They define the service point and everything on the load side of the service point is governed by the NEC.
For all of the commercial installations in our area the utility has defined the service point as the secondary terminals on the transformer that supplies the service.
However, even where the conductors in question are utility owned, the National Electrical Safety Code, has the same clearance requirements. In general utilities are governed by the NESC.

The NEC has no jurisdiction over the utilities. The ESR (Electrical Service Requirements) is an installation manual used by Southern California Edison.

 

[Tanelectrical]

The NEC has no jurisdiction over the utilities.

So would 3 feet from the edge and 3 feet above meet the utilities requirements

 

[don_resqcapt19]

The NEC has no jurisdiction over the utilities. The ESR (Electrical Service Requirements) is an installation manual used by Southern California Edison.

I did not say the NEC had jurisdiction over the utilities. I said that the NESC does. The National Electrical Safety Code published by IEEE is the code of regulations used by the utilities. In general the things like overhead clearance are the same as in the NEC. The utility service rules are just their internal rules with some NEC and NESC requirements thrown in for clarity.

In general utilities are governed by the NESC.

 

[Tanelectrical]

I did not say the NEC had jurisdiction over the utilities. I said that the NESC does. The National Electrical Safety Code published by IEEE is the code of regulations used by the utilities. In general the things like overhead clearance are the same as in the NEC. The utility service rules are just their internal rules with some NEC and NESC requirements thrown in for clarity.

I got ahold of the local utility company and they said my height looks good but my inspector is city so he should pass my installation right ?

 

[mtnelect]

Go to your Utility website and check their ESR.
Attached is my ESR for Southern California Edison.

 

[Tanelectrical]

Go to your Utility website and check their ESR.
Attached is my ESR for Southern California Edison.

My local utility has a drawing and it just says 3 foot clearance from roof I talked to the local utility engineer who was at the job on Tuesday and they told me my clearances looked good from what he remembered. Hopefully the city inspector passes it I am over three feet above the roof but I am less than three feet from the edge of the roof to the wire

 

[mtnelect]

My local utility has a drawing and it just says 3 foot clearance from roof I talked to the local utility engineer who was at the job on Tuesday and they told me my clearances looked good from what he remembered. Hopefully the city inspector passes it I am over three feet above the roof but I am less than three feet from the edge of the roof to the wire

Sounds like you are doing your due diligence. The only one left is the City Inspector, give him a call.