Equipment Disconnect

[pete m.]

A local utility here in OH is offering primary metering to larger commercial/industrial facilitys. As part of this offering the "service point" is also changing. Typically, on mid-sized manufacturing facilitys the utility would own the power transformer and define the point of service as the secondary bushings of the transformer. Now after the primary metering is installed, the utility is giving ownership of the transformers to the customer along with the MV cabling, etc... In particular, 490.22 requires a means of isolation for equipment. This means of isolation would, by default, become the service disconnect. Would 490.22 actually require a disconnecting means to be located in the primary to the transformer? If this is the case, what other NEC implications would come into play with this change of ownership? Looking for opinions......
Pete

I apologize for posting twice.... please forgive my ignorance

(Duplicate posting has been removed) Charlie Beck

[ April 18, 2003, 05:29 PM: Message edited by: charlie b ]

 

[charlie b]

Re: Equipment Disconnect

Here?s one impact (and I may be wrong about this issue): If the utility owns the transformer, they will size it based on perhaps 45% to 55% of the load that you calculate (per NEC methods) and that you provide to them. If you own the transformer, you will have to size it for the entire calculated load.

Here?s another impact (and I may be wrong about this one as well): It is at (or near) the service point that the neutral and the ground are bonded together, with a connection from that point to the grounding electrode system. If the utility owns the transformer, then this bonding takes place at your service switchgear, and there is no EGC between the transformer and the switchgear. If you redefine the service point as you have described, then the bonding (and the connection to the grounding electrode system) must take place at the secondary of the transformer. This also means that you must run an EGC from the transformer to the switchgear.

 

[bennie]

Re: Equipment Disconnect

I do not think that ownership is relevant. This falls within the NESC.

The utility will retain a degree of responsibility and liability regardless of ownership. The utility must install this according to the NESC.

 

[pete m.]

Re: Equipment Disconnect

Bennie, I agree with you to a point, the utility will be responsible for only the equipment they own. The quandry that I see is that the NESC will (I assume) have different guidelines for installation. The NEC, however, per 90.2, will have jurisdiction over the installation after the service point and the problems start when you tell the proud new owner of this equipment, that once was under the exclusive control of the utility, that they will be responsible for providing equipment and methods that comply with the requirements of the NEC. This, in some cases, could render a considerable cost. Although I am a firm believer in the saying "If it aint broke, dont fix it", because of this change in service point it changes responsibility (more like liability) of the methods for safety. without exercising 90.4 how can this change in service point come to a conclusion that will satisfy the NEC and not slam the facility owner with a cost that prior to the change would not have needed to be incurred?
Pete

 

[bennie]

Re: Equipment Disconnect

Contact the public utilities commission for your state. There is some legal reason for the utility assigning the equipment over to the owner. I think it will revolve around property easements.

The procedure for the installation should be worked out among the responsible parties.

The NESC should prevail.

 

[charlie]

Re: Equipment Disconnect

Pete, Charlie, and Bennie, the service point is where the customer takes over ownership and control of the facilities. If the electric utility retains ownership and rents the facilities to the customer, nothing changes except for the location of the cash register . . . UH . . . meter. No disconnecting means are required since everything is still under the exclusive control of the electric utility and falls under the NESC. However, if the electric utility turns over complete ownership and control of the facilities, then a ground operated disconnecting device and OC protection must be provided close to the service point.

I would give you Code references but I don't have my copies of NEC and NESC home with me.

 

[iwire]

Re: Equipment Disconnect

All I can think is this "gift" of the transformer is going to cost big time if it decides to go, and needs to be replaced.

Besides the actual replacement cost wouldn't this be the time when any differences between the NEC and NESC would have to be addressed.

Also with primary metering now the customer gets to pay for keeping another transformer warm.

It sounds like a great deal :roll:

[ April 19, 2003, 12:06 PM: Message edited by: iwire ]

 

[charlie]

Re: Equipment Disconnect

Actually, Bob, it is a great deal. The electric utility doesn't have to maintain the facilities any more. And the customer gets his electricity at just a small cut above what it takes to generate it. Unless the transformers let go early in their life, the customer will make out big time on the primary meter rate.

In Indianapolis, we have a Standard Contract Rider No. 4 available, which allows us to charge the value of the entire installation (broken down in a per month basis) every five years for rental of the customer facilities. Believe it or not, the customer will make money from that.

If the customer wishes to own their facilities, we will sell the installation to him and he may either pay us to maintain the facilities or hire a HV contractor to do it for him. The lower cost for electricity is sufficient for him to do any one of those options. This includes keeping the transformers warm which is a legitimate cost.

 

[iwire]

Re: Equipment Disconnect

Thanks for the info Charlie, I am always suspicious of deals like this.

If this is truly going to save the customer money then that would mean it must cost the POCO some money (the saved money has to come from somewhere) which makes me wonder what the POCOs motivation for this would be.

I do not look at the POCO as evil but most are in business to make money (nothing wrong with that) so why would they make a change that would cut profit.

Bob

 

[pete m.]

Re: Equipment Disconnect

Originally posted by charlie:
Actually, Bob, it is a great deal. The electric utility doesn't have to maintain the facilities any more. And the customer gets his electricity at just a small cut above what it takes to generate it. Unless the transformers let go early in their life, the customer will make out big time on the primary meter rate.

In Indianapolis, we have a Standard Contract Rider No. 4 available, which allows us to charge the value of the entire installation (broken down in a per month basis) every five years for rental of the customer facilities. Believe it or not, the customer will make money from that.

If the customer wishes to own their facilities, we will sell the installation to him and he may either pay us to maintain the facilities or hire a HV contractor to do it for him. The lower cost for electricity is sufficient for him to do any one of those options. This includes keeping the transformers warm which is a legitimate cost.

Charlie, does the utility then obtain permits for the work that they will be doing (assuming that system changes are made) on the now customer owned equipment?
Pete

[ April 19, 2003, 05:46 PM: Message edited by: pete m. ]

 

[charlie]

Re: Equipment Disconnect

Bob, you are right. However, the electric utility may have a problem with manpower. If the customer owns the facilities, the utility doesn't have to maintain them. This is something that can be a win ? win situation. Of course, there can be other reasons but I don't know what they are. I do know that my company keeps an eye on larger customers and puts them on different rates, if they qualify and we can save them money. We make a conscience effort to treat our customers fairly (that is not BS, it is fact). Also, this would give a lot of work to a company that specializes in HV maintenance.

Pete, it depends on the area. In Indianapolis . . . I think it best not to continue with that answer. If we were in a one-on-one situation, I would give you a complete answer. I am not sure I would give you an answer to that question in an e-mail either. I would assume in most areas, the electric utility would be required to pull permits and get the work approved since they can be working on the load side of the service disconnecting means and are required to follow Article 225.

 

[gwz2]

Re: Equipment Disconnect

I'm rather cynical about Poco doing work per the NESC on the premises side of the Service Point.

I am not referring to the 'metering' work on the premises side of the Service Point.

 

[tray640]

Re: Equipment Disconnect

My boss is installing a wastepale cleaner 2 feet away from a 460 volt disconnect .I know this is not permisable.can you send me the code on this application

 

[charlie]

Re: Equipment Disconnect

I'm rather cynical about Poco doing work per the NESC on the premises side of the Service Point.

Glenn, we'll talk about it the next time we meet (assuming one of us remembers this conversation). LOL