Service Point

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augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
I have a rather unique installation where I would like input as to "service points".
I have an industrial facility supplied by a local utility at 12 kv. The metering is on the 12kv line as the OH conductors enter the facility.
By agreement, the power company installs and maintains the lines beyond the metering point. In some cases the power company installs the primary conductors to power company owned and maintained pad transformers.
In other case the transformers are owned by the facility and the power company lines terminate at a set of 12kv fuses ahead of transformers.
The situation I have encountered is addressing the various supply points as services or SDS units. They are in the process of adding some 4350 kva 12kv/575 kva facility owned transformers as well as some 2500 kva 12kv/480 power company pad transformers. All feeding various sections of the facility.
It would appear to me that the facility owned systems would be SDS whereas the POCO owned pads would be services.
The way the NEC approached 250.30 especially in light of '11 addition of 250.30(A)(2) presents a bit of a problem.

Input appreciated.
 

pfalcon

Senior Member
Location
Indiana
Service. said:
The conductors and equipment for delivering electric energy from the serving utility to the wiring system of the premises served.

The definition for "Service" does not depend upon who owns or maintains the hardware.

Imagine hiring the POCO to provide down to the 480 disconnect on a machine tool in the plant. To claim the overhead buss was anything other than part of the wiring system of the premises would be ridiculous.

I think the trick to evaluate here is to go inside-out and not outside-in to assess. This doesn't mean the POCO won't use its own rules on its equipment. But the line doesn't move.
 

Smart $

Esteemed Member
Location
Ohio
The definition for "Service" does not depend upon who owns or maintains the hardware.

Imagine hiring the POCO to provide down to the 480 disconnect on a machine tool in the plant. To claim the overhead buss was anything other than part of the wiring system of the premises would be ridiculous.

I think the trick to evaluate here is to go inside-out and not outside-in to assess. This doesn't mean the POCO won't use its own rules on its equipment. But the line doesn't move.
I agree... to a degree. I think the first question to ask is where is the service disconnecting means located with respect to the facility-owned transformer. If the mentioned primary disconnect switch is POCO controlled, then the transformer is still a service transformer. If the primary disconnect is controlled by customer, then the transformers will likely be SDS. I say will likely be because another aspect to consider is whether the POCO MGN is bonded to the secondary's grounded conductor. I don't know of any requirement (by the NEC) that prohibits the POCO MGN from being directly bonded to the secondary's grounded conductor. If it is, it is a non-SDS system... but I think this is an unlikely possibility for pad mounts.
 

Hv&Lv

Senior Member
Location
-
Occupation
Engineer/Technician
I have a rather unique installation where I would like input as to "service points".
I have an industrial facility supplied by a local utility at 12 kv. The metering is on the 12kv line as the OH conductors enter the facility.
By agreement, the power company installs and maintains the lines beyond the metering point. In some cases the power company installs the primary conductors to power company owned and maintained pad transformers.
In other case the transformers are owned by the facility and the power company lines terminate at a set of 12kv fuses ahead of transformers.
The situation I have encountered is addressing the various supply points as services or SDS units. They are in the process of adding some 4350 kva 12kv/575 kva facility owned transformers as well as some 2500 kva 12kv/480 power company pad transformers. All feeding various sections of the facility.
It would appear to me that the facility owned systems would be SDS whereas the POCO owned pads would be services.
The way the NEC approached 250.30 especially in light of '11 addition of 250.30(A)(2) presents a bit of a problem.

Input appreciated.

We have a couple of areas close to what you are describing. The metering point isn't necessarily the delivery point. On the ones we have, we will suply and maintain some transformers, but for specialty XF's, the customer must supply them. We willl still supply and terminate the wiring to the PMT XF, aven though it is a couple of hundred feet from the metering point.

Of course, as Smart$ pointed out, the disconnects are controlled by us, not the quarry. We set point of delivery at the secondary side of the PMT, or in one case, the secondary side of the overhead platform bank.
 

kwired

Electron manager
Location
NE Nebraska
Read the informational note after the art 100 definition of "service point"

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



Informational Note: The service point can be described as the point of demarcation between where the serving utility ends and the premises wiring begins. The serving utility generally specifies the location of the service point based on the conditions of service.

Since it is an informational note it is not a code requirement but I think it helps to use it to make a decision. I feel this point needs to be agreed upon by the POCO, installer, AHJ, and even the owner.

POCO probably has the most say, and usually has SOP for this, it is the special cases where an agreement maybe needs to be made.

In general if POCO installs and maintains it, then it is on their side of service point regardless of whether or not they actually own it.

They potentially could have equipment inside a customers building, but they generally don't want that liability so service point will usually be at very least at the entry to a building or maybe inside a transformer vault.
 
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