Point of Connection - 2005 NEC

[roncom0351]

Both the 2005 NEC and the 2007 NESC define the service point as "The point of connection between the facilities of the serving utility and the premises wiring".
I work for a entity that owns our own 138KV Substation with 3 XFMR's reducing down to 12,700 volts. In addition we feed 12.7 to our Central Plant Loop Switch which in turn feeds a 12.7/480 transformer.
My co-inspector and I disagree as to the "service point" he indicates it is before the 138KV substation (as we do not own the line feeding the substation" and I think it is after the 12.7/480 transformer, because if a power meter were installed this is where the CT's would be installed.
Any other thoughts on this matter?

 

[shepelec]

Think of it this way.

Where the utility connects to your equipment is the service point.
The NEC does not cover utility wiring or equipment.

 

[charlie b]

I disagree with you both, although I think your co-inspector's view is closer to (what I perceive to be) the truth. I think it is not before the substation, but inside it. The utility owns the wire coming into the substation, and that wire has to land somewhere inside your equipment. I think the "service point" is the point at which their wire lands on your equipment.

 

[nollij]

Where I work, we own our main substation, the 115kV->13.8kV XFMRs, the open air switches, SF6 breakers, and poles in the yard where the utility comes in. The service point is where where the utility lines terminate (line of demarcation) although we own the equipment (poles) that the lines are run on to that point. The metering for the utility however, is located on the 13.8kV incoming lines from the XFMRs and the meters are located inside of our main substation.

Chuck hit the nail right on the head.

 

[steve66]

I agree with Charlie. Normally, the utility company has their own codes, rules, and standards they have to follow for their wiring to your service point. From that point on, the AHJ has jurisdiction with their adopted code (usually some version of the NEC).

So normally the entire electrical system is regulated. At the least anything inside or close to an occupied premisis is usually regulated.

If the inspector agreed with your "service point", it would eliminate any and all rules and regulations for a large portion of your facility. I don't really think that would be in anyone's best intrest.


Steve

 

[iceworm]

ron-

I've worked a lot of industrial, and my experience has been, for an industrial installation, with a customer owned substation, it is where ever the customer and the Utility decide it is. I've never seen it upstream of the incoming disconnect switch, nor downstream of any secondary disconnects that are inside of the substation. However, I'm sure there plenty of screwy installations everywhere.

The issues that seem to matter are:
1. Is the utility under contract to pull the maintenance on the transformer?

2. Is the metering on the primary or secondary?

I've never heard of the AHJ caring other than they wanted to know where it was. If if weren't for the fact the electrons behave differently once they cross the service point that probably would not even matter.:roll:

In addition we feed 12.7 to our Central Plant Loop Switch which in turn feeds a 12.7/480 transformer.[\quote]
I'm really surprised there is only one 12.4/480V transformer. Considering the customer installed a substation, I would have expected several spread around the facility. And with several MV/LV transformers, the metering would be in the substation.

However, if there is only one MV/LV transformer, then 480V metering will work fine. It would be a bit odd, but it will still work fine. Thy utility and the customer negotiate the tariffs to pay for heating the transformers.

So, as for the service point, get a one line, and pick one - and get the utility to go along with it. Or ask where the utility and the customer have decided it is. Probably the first question I'd ask is, "How much of this stuff does the utility pull maintenance on?" That always a good spot to pick the service point.

W

 

[IslandSparky]

I disagree with you both, although I think your co-inspector's view is closer to (what I perceive to be) the truth. I think it is not before the substation, but inside it. The utility owns the wire coming into the substation, and that wire has to land somewhere inside your equipment. I think the "service point" is the point at which their wire lands on your equipment.

I disagree vehemently with you on this-- we have a common case in California where you have primary metering, with customer-owned, but utility maintained equipment to the 480V main service disconnect. Technically, you could argue your position that this utility-maintained equipment is under the NEC, but the reality is that it is just a contractual issue.

The NEC is woefully inadequate at addressing campus MV systems-- non UL equipment such as a PME-9 just don't fit. There needs to be a balance when it comes to the gaps such as this.

 

[wireguy8169]

Though this may be a simplistic way of looking at it, point of connection in my understanding of the word would be whereever the first point (could be multiple if you have redundancy) of connection from the utility is to your equipment. As far as who is responslible for what, that is a contractual issue that should be outlined by the utility...

 

[tom baker]

I disagree vehemently with you on this-- we have a common case in California where you have primary metering, with customer-owned, but utility maintained equipment to the 480V main service disconnect. Technically, you could argue your position that this utility-maintained equipment is under the NEC, but the reality is that it is just a contractual issue.

The NEC is woefully inadequate at addressing campus MV systems-- non UL equipment such as a PME-9 just don't fit. There needs to be a balance when it comes to the gaps such as this.

The 11 NEC adds Article 399 that may help.

 

[hurk27]

We have many primary metered services, and all primary metering is done at the property line, and with our POCO, that is the de-mark, they wont touch anything after this point without a contract for pay, now some of the steel mills have some kind of co-generation systems, and the lines get blurry from what I'm told, but all of the other plants or even camp grounds and trailer parks, we have here are done this way, and if we loose a MV feeder under ground they have to pay to have them fixed.

this question can be very utility dependent, and state utility laws and regulation might come into play, state by state?