Service conductors

[bthielen]

I have not been able to understand the difference between service-lateral and service-entrance conductors?

I live on a farm and power comes from my electric supplier to a pole where the transformer is located. From there it goes overhead to another pole down to my meter. Under the meter I have a load distribution panel to distribute the power to each of my buildings. Am I correct that the service-lateral conductors are those from the transformer to my meter and distribution panel and the service-entrance conductors are those from the distribution panel to my individual buildings?

I have read the definitions in the 2002 code book but am still not entirely clear.

I appreciate the education.

Bob

 

[charlie]

Re: Service conductors

A service drop is from the last pole to the point on the building that supports the "drop", overhead.

A service lateral is from the last electric utility's equipment to the building, underground.

The service drop or lateral extends to the service point whether wires, cable, or meter fitting.

The service entrance conductors are those conductors that extend from the service point to the service equipment. Remember that the cash register (meter) is not service equipment; instead, think of the metering equipment as a wide place in the conduit.

On a farmstead, you are required to have a Site-Isolating device at the distribution point. If you elect to not have any OC protection at this point, the downstream wires and cables will still be considered to be service entrance conductors.

This is all paraphrased since you were having trouble with the Code language so I would expect you to find holes in my daffynitions.

 

[bthielen]

Re: Service conductors

Thanks.

Inside my distribution panel there is a main circuit breaker with additional branch circuit OC for each building. If I understand you correctly, my supply is not considered a service-lateral at all and what I have is a service drop. Since my distribution panel consists of a main breaker and branch circuit breakers for each building, I really don't have a service entrance either and the individual branch circuits supplying the buildings are just that, branch circuits?

Bob

 

[charlie]

Re: Service conductors

IMO you are mostly correct. Your service entrance conductors run from the service point down to the service equipment. I would assume you will have a disconnecting means and panelboards (probably in the same enclosure) in each building so the circuits running from the service equipment would be feeders and are required to be four wire (two phase wires, a grounded conductor, and a grounding conductor).

Also, Article 547 is outside my expertise so my answers are a little suspect.

 

[al hildenbrand]

Re: Service conductors

Bob,

If I have caught this correctly, the farmstead service that you have is one of the common configurations.

In my experience, the span of conductors, running pole to pole from the transformer to the pole your meter is mounted to, are the service drop conductors.

At the top of the meter pole, the service lateral conductors connect to wires that you own and run down the pole, through the meter socket and, in your case, end at the line side of the "main breaker" as you called it, the service disconnect. These conductors are the service conductors.

The conductors that then run from individual breakers in the distribution box to the outlying buildings and the dwelling will be feeders.

The service point is the point at which the power company connects its conductors to your conductors, and in your case, I suspect is at the top of the pole your meter is mounted to. Your local PoCo will be able to verify as practices from PoCo to PoCo varies.

[ October 10, 2003, 11:54 PM: Message edited by: al hildenbrand ]

 

[bthielen]

Re: Service conductors

Very much appreciate the info. I am considering replacing the overhead feeders to one of my buildings and couldn't quite be sure which part of the code I needed to follow for wire sizing. It's a small storage shed, 15' x 30', and my calculated load is nothing more than the general lighting load and maybe two to three duplex receptacles. It seems there are some different specifics depending on whether the wires are service-lateral vs. service-entrance or branch circuit feeders, etc.

You have helped considerably. As a home-owner I surely do appreciate the information and knowledge I am able to gain from this forum. At the same time, as an individual in a related field, I can't help but feel a little uncomfortable at times asking for information that might be leaning a little more toward professional knowledge that your experience has given you and is recognized by your licensing.

Thanks again,

Bob

 

[charlie]

Re: Service conductors

In my experience, the span of conductors, running pole to pole from the transformer to the pole your meter is mounted to, are the service lateral conductors.

Al, I hate to do this to you but the NESC which is published by the IEEE says, "Service Drop. The overhead conductors between the electric supply or communication line and the building or structure being served." This is the Code I work out of most of the time.

The NEC says, "Service Drop. The overhead service conductors from the last pole or other aerial support to and including the splices, if any, connecting to the service-entrance conductors at the building or other structure." It also says, "Service Lateral. The underground service conductors between the street main, including any risers at a pole or other structure or from transformers, and the first point of connection to the service-entrance conductors in a terminal box or meter or other enclosure, inside or outside the building wall. Where there is no terminal box, meter, or other enclosure, the point of connection is considered to be the point of entrance of the service conductors into the building."

 

[al hildenbrand]

Re: Service conductors

oops

Yes, service drop is what I meant to say. . .

Thanks

 

[charlie]

Re: Service conductors

Sorry Al, after taking another look at what I wrote, I was rather harsh. I don't have much experience with farmsteads and Indiana doesn't recognize 547 but I do know the utility side of our business (well, most of it on the distribution end).

I assume the rest of the answer is OK (that is the part where my knowledge is not solid).

 

[al hildenbrand]

Re: Service conductors

Hey! No worries, Charlie. The clear and correct use of language is at the core of this forum, seems to me, and I deeply appreciate the opportunity to participate. I hone my skills with your and every ones help.

I started my career in eastern Nebraska with my brand new BS in EE working with a small municipally owned power company that covered a town of 20,000 and the outlying rural areas for about 30 miles. I moonlighted as an electrician back then, before any state wide licensure. So, my utility side knowledge is largely unique to that experience. I did get to see a fair amount of farmstead hookups over the years, and an awful lot of it was ruled by the common sense dictum: "If it ain't burned down by now, it's safe!". Stunning examples of applying too much cheap labor to assemble something with too little money for material.