Service or something else?

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jtinge

jtinge

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Hampton, VA
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Sr. Elec. Engr
It seems to be a common practice to refer to the electrical supply to a building as the service whether it is supplied from a utility or from a site owned feeder, especially in specifications and some design standards.

When the electrical supply to a building is an outside feeder from site owned switchgear, transformers and generators, is it appropriate to refer to to the supply as a service.

If not, what would be the correct descriptor? Would there be analogous to a service point at building fed by a feeder?

My concern is that the use of "service" to describe the electrical supply to the building implies use of Art 230 Service requirements and not Art 225 Part II and 250.30 and 32 Outside Feeder and SDS requirements.
 
jtinge said:
It seems to be a common practice to refer to the electrical supply to a building as the service whether it is supplied from a utility or from a site owned feeder, especially in specifications and some design standards.

When the electrical supply to a building is an outside feeder from site owned switchgear, transformers and generators, is it appropriate to refer to to the supply as a service.

If not, what would be the correct descriptor? Would there be analogous to a service point at building fed by a feeder?

My concern is that the use of "service" to describe the electrical supply to the building implies use of Art 230 Service requirements and not Art 225 Part II and 250.30 and 32 Outside Feeder and SDS requirements.
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As far as the NEC itself goes, a service is specifically and only from a utility. This has two major consequences:
1. There will not be overcurrent protection on the incoming wires.
2. The wiring on the "service" side of the service point will be governed by NESC rather than NEC.

If the incoming wiring comes from a feeder that does not ultimately derive its power from a utility, and if the source is something like a power coop serving a number of users, then to the extent that 1 and 2 apply, it would seem to be a service.
If it is a generating plant wholly owned by the customer, then it would be a separately derived system but not a service.
JMO, YMMV
 
Service or something else?

I don't disagree at all. I find that many specifications don't make a distinction between service or SDS/feeder. In fact service equipment specifications are often included in project specs when the electrical source is an owner's switchgear and transformer.

So to help make the distinction, what terminology should be used to describe to incoming building power when it's not a service?



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From a separate post, a campus-distribution system (typical of many I've seen) was described as follows:

The "source ends" (primary substation ends) of the center's primary distribution cables are feeders and shall comply with NEC Article 215, ?Feeders? and Article 225, ?Outside Branch Circuits and Feeders?.

The "load ends" (building ends) of the center?s primary distribution cables, however, shall be treated as the utility services to the building. Install service disconnecting means and comply with all of the requirements of NEC Article 230, ?Services?.

In a like manner, a secondary-voltage feeder (or feeders) from one building to another building shall be treated as the utility's service to the building. Install service disconnecting means and comply with all of the requirements of NEC Article 230, ?Services?.

So based on responses to this post, the requirement to treat the load ends of the feeders described above as utility services to the buildings is incorrect?

I think many industrial and campus-style complexes treat these feeders as services. I've had some rigorous debates with A-E design engineers also wanting to treat them as services.
 
jtinge said:
From a separate post, a campus-distribution system (typical of many I've seen) was described as follows:

The "source ends" (primary substation ends) of the center's primary distribution cables are feeders and shall comply with NEC Article 215, ?Feeders? and Article 225, ?Outside Branch Circuits and Feeders?.

The "load ends" (building ends) of the center?s primary distribution cables, however, shall be treated as the utility services to the building. Install service disconnecting means and comply with all of the requirements of NEC Article 230, ?Services?.

In a like manner, a secondary-voltage feeder (or feeders) from one building to another building shall be treated as the utility's service to the building. Install service disconnecting means and comply with all of the requirements of NEC Article 230, ?Services?.

So based on responses to this post, the requirement to treat the load ends of the feeders described above as utility services to the buildings is incorrect?

I think many industrial and campus-style complexes treat these feeders as services. I've had some rigorous debates with A-E design engineers also wanting to treat them as services.
Click to expand...

Unless the supply comes directly from a utility they are feeders and need to be treated as such.

However the rules for feeders supplying buildings and for services are almost identical as far as the equipment type required, as far as a grounding electrode system. The only real difference is the bonding of the neutral and that was acceptable up to just a few code cycles ago.
 
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