Service entrance condutors

[pierre]

Re: Service entrance condutors

One of the problems with the definition/location of the Service Point is; we have one NEC and hundreds if not thousands of different POCOs. In one area we do this, in another area we do that, etc...

So we in our 'own' areas try to make it work.
The idea of where the Service Point is can be opinion as to where we want it to be.

My thoughts are based on the present NEC definition, is where I want it to be. The POCO has a concern about theft of services, we want control of what we wire. I say if they want control of it let them wire it. There is a swinging change in the amount of work we do versus the POCO. What I mean by that is, they run less cable than they use to, we run it now. And they are providing less service, in NY we are now required to make the LIVE service connection where the POCO used to do it. As a matter of fact, When I first started in this industry, we were not permitted to make or even touch that work. What will we be doing next? I do not know about other areas, but how many guys have their men or themselves are making these connections with the proper training and PPE?

What was this thread about?

Pierre

 

[iwire]

Re: Service entrance condutors

Pierre I did not think you where rambling I feel much the same as you, if the POCO wants control let them wire it. I also agree that every area is different and we each think we do it the "right way"

When I wire it I use the NEC, but if it is under POCO control wouldn't I be using their specs. (NESC). The same as when I have to build a transformer pad and run the primary duct bank.

In that case the NEC inspector does not even look at it but a POCO guy does.

It is all very puzzling. plus the data that the POCO holds as to usage for a particular meter.

There have been times we have had to call the POCO to put locks on CT cabinets for safety reasons.

I believe I saw someone post that if the POCO locks the Customers disconnect shut that the customer is within their rights to cut the locks to service the switch (change fuses).

Perhaps Charlie can elaborate as to the SOP in his area.

Thanks to you all.

And I too am sorry for rambling.

 

[ryan_618]

Re: Service entrance condutors

Hello gentelmen. Sorry for not being more involved with a discussion that I started...I've been in IBC seminars all day. There is no need to apologize for rambling, as I don't believe you were rambling.

So did anybody come up with an answer? Looks like Don says there are no service entrance conductors and EPrice says the bus bars are (perhaps). I believe the bus bars are as well, but my mind could change at the drop of a hat on this one!

Since this sparked so much interest, I think I'll bring my camera to work tommorrow and take some pics of this one and other typical services in the area.

Thanks again for all of your help

 

[iwire]

Re: Service entrance condutors

Originally posted by ryan_618:
Since this sparked so much interest, I think I'll bring my camera to work tommorrow and take some pics of this one and other typical services in the area

Hey, to me this is much more interesting than which way to face an outlet or if smoke detectors have to / should be on AFCIs.

Pictures are always good.

 

[eprice]

Re: Service entrance condutors

Originally posted by ryan_618:
Looks like Don says there are no service entrance conductors and EPrice says the bus bars are (perhaps). I believe the bus bars are as well, but my mind could change at the drop of a hat on this one!

But, whether the bus bars are service entrance conductors or not, I think the suggestion that Wayne and Don made that the GEC be sized according to the rating of the panel is the easiest answer. How can I find out the cross sectional area of the bus bars? Do I have to measure them and calculate? Is that infromation given somewhere in the panel? I think the rating of the panel and the size of the bus bars are inter-related so that using the rating of the panel would give about the same answer. Does that sound right?

[ September 25, 2003, 11:02 AM: Message edited by: eprice ]

 

[bennie]

Re: Service entrance condutors

Excellent thread, very interesting, but I'll fix that

This subject is related to the change in definition of Service conductors, in 1996. This change also caused the 4/wire feeder to a separate panel.

In I993 the service conductors ended where the premises wiring system began. Notice that service equipment, and feeders are not on the list of components of a premises wiring system.

The premises wiring system started at the load side of the branch breakers, until the change in 1996. The service conductors, switches, panels, and circuit breakers were considered as service equipment, not premises wiring system.

The reason that the words "sub-panel" does not appear in the code book, is due to the fact a sub-panel does not exist on a service to a premises.

Consider 6 panels, with 100 amp mains, on the side of a residence. According to the 30 feet permitted for an auxiliary gutter, the panels can cover a 30 foot area with unfused supply conductors. Now put overcurrent devices on all the feeders, the panels then can be in any part of the building and supplied by 3/wires, the same as a service panel. This was before the experts changed the definition of service conductors.

This change was to prevent parallel load paths on the neutral/ground. It also created a higher impedance in the fault path, and a high neutral to ground common mode voltage. There is other methods to prevent parallel current, that will not produce the negative side effects.

 

[don_resqcapt19]

Re: Service entrance condutors

Bennie,
Even in the 1984 code the "premises wiring" started at the load end of the service drop or service lateral. What change are you talking about? The '96 code said the "premises wiring" starts at the "service point". How is that different from the "load end" of the service drop?
Don

 

[bennie]

Re: Service entrance condutors

The answer is in the interpretation of where the premises wiring begins. Prior to 1996 the service point was considered to be at the distribution panels. The premises wiring began at the load side of the branch breakers.

This entire system was changed by the special committee, on Article 250. This was done when the 3/wires to ranges and dryers was changed.

On an NM cable fed panel, there is no need in an equipment ground conductor from the service to the panel. Besides, a parallel path for the neutral load is not Armageddon rising.

 

[iwire]

Re: Service entrance condutors

Premises Wiring (System). That interior and exterior wiring, including power, lighting, control, and signal circuit wiring together with all their associated hardware, fittings, and wiring devices, both permanently and temporarily installed, that extends from the service point or source of power, such as a battery, a solar photovoltaic system, or a generator, transformer, or converter windings, to the outlet(s). Such wiring does not include wiring internal to appliances, luminaires (fixtures), motors, controllers, motor control centers, and similar equipment.

Service Point. The point of connection between the facilities of the serving utility and the premises wiring.

I am still very confused as to how we known where the utility facilities end and where the premises wiring begins, or more correctly where the service point is?

[ September 25, 2003, 09:08 PM: Message edited by: iwire ]

 

[bennie]

Re: Service entrance condutors

Service panels and loadcenters are important pieces of electrical equipment. I do not see them mentioned in the definition of a premises wiring system. Sub-panel is not there either. Is this a conspiracy to confuse?

Check out the definition of service equipment. This appears to be remote from the definition of premises wiring system.

 

[don_resqcapt19]

Re: Service entrance condutors

Bennie,
The code very clearly stated, prior to 1996, that the premises wiring system began at the load end of the service drop or lateral The code changed the wording in '96 to say at the service point. I think that the older wording was better, but in either case the service disconnect and everything on the load side of the service disconnect is part of the premises wiring system.
Don

 

[pierre]

Re: Service entrance condutors

Bennie

Here I am in my study trying to follow this thread and very engrossed and you post that one liner. I started laughing so loud my wife came in because she thought I was watching something funny on the boobtube. She sees I am on the forum and walks out shaking her head. Thanks for the good laugh, it was good timing.

Pierre

 

[bennie]

Re: Service entrance condutors

The definition of premises wiring system first appeared in Article 100 in 1975.

The definition of service point first appeared in 1993.

To me, the two definitions are indicating the service point is when the utility service is connected to the premises branch circuits.
Regardless of ownership of material or equipment.

You are probably correct, Don, but I don't buy it. I know of many 3/wire feeds to panels, that were installed prior to 1996.

 

[ryan_618]

Re: Service entrance condutors

This is the panel in question:

Thanks are in order to Joe Tedesco, please visit his site at JoeTedesco.com and The Websparky Dave Nix, please visit his site at grafixbynix.com

 

[pierre]

Re: Service entrance condutors

Service Point. The point of connection between the facilities of the serving utility and the premises wiring.

This means to me;
In an overhead application the connection at the weatherhead between the utility conductors and the Service Entrance conductors. The conductors from the service point (connection at the weatherhead) to the first point of disconnect are service entrance conductors and they are premise wiring owned by the customer. This also means the meter can is premise wiring and owned by the customer, the meter itself is utility property, that is why we (EC) have to perform the repair of the "Service Entrance Conductors and the meterpan after storm damage.
Is this not the usual method in most jurisdictions?

In an underground situation it can be a little more complicated and I will not go there... yet.

Pierre

 

[hillbilly]

Re: Service entrance condutors

I would size the GEC according to 250-66. Note2. What is the rating of the panel? It looks like a 400A to me. This would require a 1/0 GEC if residental.

 

[bennie]

Re: Service entrance condutors

In the beginning of domestic electricity, a residence would have a fuse block and knife switch, as a service loadcenter. The electricians installed the main, and the utility connected to the supply side of the switch.

The service point was understood to be at the place where line, changed to load, in relation to overcurrent protection.

This is why a service panel, service conductors, and metering equipment is not included in the definition of premises wiring system. A premises wiring system is the equipment and material in the definition, that is under the control of the occupant.

The service point is at the main switch where only the utility lineman can shut off the power. This definition will hold up in any legal proceeding.

Those who have the responsibility, are authorized to work on the system.

[ September 27, 2003, 10:06 AM: Message edited by: bennie ]

 

[ryan_618]

Re: Service entrance condutors

For those of you who thought this thread was dull, I apologize for breathing life back into it. For those of you who found it interesting, maybe you can follow me a little farther...

My original argument was whether or not you could call a busbar a "service entrance conductor" or, to be more precise, if you could call a busbar a "conductor". I was reading 250.118(A) tonight, and I realize it is EGC's not S.E.C.'s, but I notice that it seems to imply that a busbar is a conductor. With that in mind, I think I've made up my mind that I will call the busbars of this particular application, and those like it, the service entrance conductors and require the GEC to match the rating of the can.

Thanks to all those who helped me out with this.


[ October 01, 2003, 10:57 PM: Message edited by: ryan_618 ]

 

[bill addiss]

Re: Service entrance condutors

I think I've made up my mind that I will call the busbars of this particular application, and those like it, the service entrance conductors and require the GEC to match the rating of the can.

Tada!
I think it makes the most sense.


Bill

 

[iwire]

Re: Service entrance condutors

Ryan, Does the code specify how to convert the bus bars rated in amps into AWG or kcmil in order to use Table 250.66?

Would you try to calculate the service conductor size for the bus bar rating by using 310.16?

Or would you try to calculate the cross sectional area of the bus bars?

As an installer I would go with the first one, but I do not think an inspector can require me to.

Due to the generally short length of the single conductor for the GEC it does not cost much to go up in size.

My feeling is if we consider the bus bars as service entrance conductors Note 2 of 250.66 would be not needed, there is always some busing involved even if it is between the breaker line lugs and the contacts or the same in a disconnect switch.

I know the NEC handbook commentary is not "code" but it is interesting reading for all the terms we have been using here.

Here is a highlight of what the handbook has to say, remember these are excerpts, if anyone is interested they should read the entire text.

Service Point: "The serving utility generally specifies the location of the service point."

Service Conductors: "Service conductors is a broad term and may include service drops, service laterals, and service-entrance conductors. But this term specifically excludes any wiring on the supply side (serving utility side) of the service point."

Service Lateral: "Conductors on the utility side of the service point are not covered by the NEC. The utility specifies the location of the service point. Exact locations of the service point may vary from utility to utility, as well as from occupancy to occupancy."

These are opinions just like the opinions we post, but I still feel they are interesting just like the opinions of the members of this forum.